Umbria.

We delved into Umbria on a few occasions from our base in Montepulciano (too many long drives, I have to admit). Perugia looked too big for us and we never made it into Spoleto. We did overnight in Assisi once, which was incredibly beautiful at sunset. Spello is gorgeous and hilly, a good base for the rest of the eastern side of Umbria (prettier than the western side). You can hit many other towns and villages on the eastern side from here - Gubbio, Montefalco, Bevagna, Perugia, Spoleto, Trevi, Montone, enough to take up your time. Assisi is worth a revisit for me. We spent a day around Norcia, which I really liked, but I don't know the state of it now.

I've stayed in all these places, and would choose Spello plus day trips - no need to stay in two places, IMHO.

I can not say enough good things about Assisi . . . especially at night. For 16 years I spent 2 weeks there as part of an international music festival. It's a place, for me, of great beauty and peace. The tour groups come in late in the morning and leave in the middle of the afternoon. Even so, there is plenty to see and lots of streets to roam about in this medieval city. The evening hours are pure magic. The Piazza Comune is the city's living room. Often there are groups of young people, pilgrims, caught up in the spirit of St. Francis, singing and dancing. There are several wonderful cafes for a cool drink or coffee. As the sun begins to descend I would walk past the church Santa Maria Sopra Minerva and take the road on the right. There will be several places to stop and get caught up in the beauty of the valley at sunset. At the Roman gate turn a sharp left and the Basilica San Francesco is right in front of you. When it is lit against the star filled sky, take a deep breath and remember: you deserve this! I have a picture of this on my desk at home. At the edge of the baslica's lawn there is the statue of Francis, the soldier. I suggest turning left and heading uphill back to Piazza Comune. We used to joke that this walk is up hill in both directions . . . and it is. For day trips, Spello, Perugia and Orvieto are all possible and worthwhile. Honestly, for me, Assisi at night is a given on my schedule. And for me, the place to stay would be near the Piazza Comune and the Basilica Santa Chiara.

We spent two weeks in lovely Spello. It was a wonderful base for exploring other towns and cities. We enjoyed day trips by car toMontefalco, Bevagna, Assisi,Norcia, Todi, Perugia.

we've stayed in Perugia and Spello on some trips, and have visited the other towns mentioned. You really can't go wrong with any of them. Perugia, being a bit larger town, has a car rental office right at the train station so that is a convenience.

We are planning a week in Umbria in Oct of 2021 and will likely stay in Perugia as our base.

I loved Spoleto and it is on my list to return as soon as I can which will not be in 2020. Spoleto is well planned to enjoy. The elevator infrastructure to access the upper town is amazing and the upper town has many charms. I'm hoping that when I return the aquaduct bridge will be open;it was closed because of concern about safety due to earthquakes in the region. Lots of beautiful walking on the other side.
Asisi is also a place I loved, especially in the mornings and late afternoons after the the tours depart. I would definitely stay in Asisi instead of Spello, which is worth a trip but the train is only 20 minutes away. In fact walking to Spello from Asisi or vice versa is only a few hours walking,a 2 h 24 min (10.8 km) via Via delle Regioni.
Don't miss Orvieto sitting high on the tufa bluff, I will often make Orvieto my first or last stop when I am in Umbria because it's only 1.5 hours from Rome by train so it's wonderful for a first or last night (s) when arriving or departing from Rome.

There is also Cortona which is high hill town, small but beautiful. We stayed at a place just outside the walls-
good for parking your car.
Loved Speleto and would recommend. Spello is a little smaller but still lovely.

I'll put in a plug for Todi. I spent a full week there on my last trip and loved it. Walking down the ramparts after a dinner at the top of the hill was magical - though all the families, including young children, were usually just walking up for dinner when I had already finished. It's big enough to enjoy for a week, and also a good base for day trips by car. There is no train station, but I'm sure there are buses if you're not driving. There was plenty of free parking outside the wall. My apartment was inside the wall near the bottom, so it was always a climb up to do things. But there were many different ways to get to the top. I highly recommend Todi.

I appreciate all the replies! I am looking at Todi now - great suggestion. We will be traveling by car, it's just my preferred way of getting around. I like that you can come and go as you please, no time waiting around in train stations, and can stop anywhere along the way that you want for as long as you want. I can't wait until its safe to travel again!!

Dear Highwayman, Sun 1.50pm

You have received some great suggestions here.

A bit slow in posting but have not checked into this site for a week or more.

My experiences from the time my family spent a week in September 2018 in Umbria. 10 Adults and 5.15 children.
As we are usually a large group, agritourismo’s provide the best outcome for us. Normally away from the popular areas. Save for airports, I have not spent time in big cities like Paris or Rome since 2010.

Just to the east of Todi we took the Castello di Petroro Villa for a week. Commanding views to the north over farmland with vineyards and olive groves. What else should one expect! Ample agritourismo accommodation choices around Todi region.

We were into our 3rd week in Italy and took this villa to relax a little, catch our breath and let the children have fun swimming in the pool. From it we drove to Largo Trasimeno and spent an immensely enjoyable day including lunch by the lake. Another day we drove to Norcia and surrounds. An afternoon was taken up in Todi. In the late afternoon we were caught in a magnificent thunderstorm, lasting about 15 minutes, that left us a little damp. Dinner at the Umbria restaurant, which had beautiful evening twilight views over the rural district to the east of Todi and excellent local fare.

On other days we purchased local wine, beer, produce and cooked or BBQed the meat or poultry and dined by the pool. Scouring the countryside for local produce took us to out of the way places, including my now favourite Umbrian village of Bastardo.

On one day a daughter and her husband took an early morning train from Terni into Rome for the day. It was his first time in Italy. Took about an hour on the train.

The countryside is a delight to drive through as autumn approaches. Lovely orange, brown and yellow hues. Abundance of freshly harvested produce to purchase in the small villages. Bonus is that only the investigative tourists venture to these areas. In general, the vast majority of the area is yet to be spoilt by over tourism. Real people living real lives.

We had planned this year for 12 weeks in Europe, late summer into autumn including northern Umbria. Will have to wait to 2022.

Stay safe.
Regards Ron

should I split my nights between two places or stay in one and explore the surroundings from one home base (will have rental car).

I'd stay on one place. The region isn't that big, so you can easily drive to all the places you want to visit. And seeing the countryside is part of the charm; you might even be driving by some small town not in the guidebook and decide to visit. We've done this several times and they have been some of the best experiences.

Also moving to a new hotel is a bit of a hassle; you'd probably want to go in the morning and so the new room is unlikely to be ready. If you plan on stopping somewhere along the way that means you leave all your luggage in the car. Italy is generally safe, but nobody is going to break into your car and take your luggage when its back in your hotel room. It's a small risk, but one I prefer to avoid if possible. As a side note, never open your trunk with luggage in it to get things at a stopover. Stop a mile or so before the destination and get whatever you need out.

no time waiting around in train stations

On the other hand, you'll have to park outside the city center and walk in. Not a problem in small walled villages, but it can be time wasting in towns and cities. Not to mention the risk of ZTL fines, highly regulated parking, speed traps and car break-ins.
If your suitcases are in the trunk, you simply can't "stop anywhere along the way that you want for as long as you want".

Both options have positives and negatives aspects.

Let me cast a vote for Spello. We stayed there for 6 nights and used it as a base to explore the region. The village is known as the city of flowers. In June they host "Infiorata" one of the premiere flower events in all of Europe.
We also loved Perugia, and obviously Assisi.

We enjoyed a day in Perugia but think it would be difficult getting in and out
of the city for day trips. And there is a strict ZTL too.

It's not hard getting in and out of Perugia for the day. Just drive to the big free parking lot. Put "Piazza Umbria Jazz" in your maps app. Take the minimetrò up to the center and back, €1.50 each way. Fun and easy and no worries about parking or ZTLs.