Europe in May 2019

I suspect most will advise a reduction in destinations, given the time you have.

You have a plan to cover 2400km in the time an RS tour takes to cover 1500km ( Best of Italy) You will not have the benefit of a dedicated bus for door to door delivery to make best use of time.

Here is a map of you destinations. You can start in Paris head east and finish in Berlin. Or do the reverse or start in Budapest head west to Paris and end in Berlin

https://www.google.com/maps/dir/Paris,+France/Salzburg,+Austria/Vienna,+Austria/Budapest,+Hungary/Berlin,+Germany/@49.8992347,6.2062698,6z/data=!3m1!4b1!4m32!4m31!1m5!1m1!1s0x47e66e1f06e2b70f:0x40b82c3688c9460!2m2!1d2.3522219!2d48.856614!1m5!1m1!1s0x47769adda908d4b1:0xc1e183a1412af73d!2m2!1d13.05501!2d47.80949!1m5!1m1!1s0x476d079e5136ca9f:0xfdc2e58a51a25b46!2m2!1d16.3738189!2d48.2081743!1m5!1m1!1s0x4741c334d1d4cfc9:0x400c4290c1e1160!2m2!1d19.040235!2d47.497912!1m5!1m1!1s0x47a84e373f035901:0x42120465b5e3b70!2m2!1d13.404954!2d52.5200066!3e0

Does your 15-17 days include getting to Europe? If so, you have 12-15 days on the ground in practice.

Many of your places can occupy you for a week, but to scratch the surface, Paris is a 5 full day city minimum. Berlin is a 4 full day city minimum. The others are 3 full days minimum.

Moving location is going to cost you half a day door to door. I therefore suggest, subject to how many days you actually have, that you have time for Paris and Berlin plus say Budapest, which would be my top 3 from your list. Fly open jaw whichever works out best for your home airport. Look at rome2rio.com as a guide to plan your route.

Flights within Europe for May have been available for months, so you may have missed the best prices.

Count exactly how many nights you will be in Italy. Subtract 1 and this is the number of days you have. The day you land doesn't count because you will probably by wiped out and jetlagged. The day you leave doesn't count because you need to leave your hotel about 4 hours before flight time. The rule of thumb is that you use about 1/2 day each time you move, so for every X days you want to spend in a city, you need X+1 nights there. Berlin and Paris need at least 3 full days. The others at least 2, though even that is just a taste of Budapest. Do the math.

Budapest/Vienna/Salzburg is a "straight line" by train. Salzburg to Berlin is 6-6.5 hours just on the train (well, 2 trains). Flying would probably save a an hour or two. You'd need to fly to Paris from any of those cities.

https://www.vikingrivercruises.com/cruise-destinations/europe/romantic-danube/2019-budapest-nuremberg/index.html

Have you considered a river cruise? They start in Budapest and end near Munich. After debarking you can side trip to Salzburg or many river cruises have it as a shore excursion. You spend your nights traveling thus minimizing time at airports or train stations.

Both Paris and Berlin are geographical outliers. I would pick one and save the other for the next trip. It’s tempting to try to see it all, it it’s also exhausting.

I generally plan the way Chani suggests. I start by looking at a specific place. I research the sights and decide which are my "must sees". Since it's you and husband, you should agree on must sees. I also research a lot of "nice to see if I have time" sights. I then plan 2 must sees per day - unless the sight is unusually large (Versailles needs a full day) or small (Orangerie needs no more than an hour).

A typical day is getting out of your lodging, eating breakfast, making your way to your first must see. Roughly three hours there. Lunch between the morning and afternoon sights. Several hours at your afternoon sight. After that, you have some time before dinner. How do you feel? Do you have energy to visit a "nice to see" sight? If yes, pick something. If not, relax for awhile before dinner. Ask yourself the same question after dinner. Do you want to do something that is open in the evening or are you done for the day? I find trying to force yourself to do more than two major sights a day starts to feel like a forced march rather than an enjoyable vacation. If you're up for another sight, have an idea what's available but don't make it a do or die thing.

Having said all that. Define your must sees, divide by two, and that's how many days you should plan in a city. Like Chani said, if you need two full days, plan three nights with travel days on either side. Three full days? Four nights...

If you looked at my itineraries, you'd think my focus was on nights (where I'm staying each night) but it really starts with giving myself time to explore each destination.

Don't forget to plan travel time. I think a half day from destination to destination is optimistic but doable. I generally plan a full day for travel, with no more than four total hours of transportation (car, train, plane), then see a "nice to see" sight if I have time after I've arrived.

I'd much prefer to limit my stops and see what I want to see at each rather than hurrying through a destination just to get to the next. Each time you move, you're losing valuable time to relocation so you will end up seeing fewer sights, not more.

I also try to avoid backtracking. I probably worry about it too much. Any backtracking, to me, is completely wasted time. So I put my destinations in a logical order, fly into the first city and fly home from the last. If I fly roundtrip from one city, I plan the trip as a loop rather than an out and back(track).

It's worth repeating what Brad said: "Each time you move, you're losing valuable time to relocation so you will end up seeing fewer sights, not more." This is so true.

Best way to determine what you have enough time for is to start adding it up. When you say 15-17 days are you including arrival and departure days? If so, you really have 13-15 days on the ground. Then add up the transportation time between your selected locations, assuming a minimum of 1/2 day for each move whether you fly, drive or take the train. You have at least 2 full transportation days. That reduces your sightseeing days to somewhere between 11-15 days (depending on my first question about days on the ground). Then do some research on your chosen locations to get an idea of how many days you want to spend there. In my opinion your locations all deserve a minimum of 3-4 full days (4-5 nights), except for Salzburg which I think is fine with 1-2 days depending on if you want to spend any time in the surrounding area (Berchtesgaden for example). I just don't think you can do all 5 in the time you have. The hardest part about planning a multi-city trip like this is to reconcile your desires with reality.

Tough choices given a span of presumably 16 full days. I like going to all of them repeatedly.

Logistically, Berlin, Vienna and Budapest are best. That would easily fit into my travel style as the night trains connect Berlin, Vienna and Budapest, ie, Berlin-Budapest, Berlin-Vienna This way you stretch out a day or two.