Aix en Province

Aix-en- Provence is a great city. With six weeks available, you should get the green Michelin guidebook to Provence. It’s available in English. It has everything. Just one little spelling hint: the entire metropolitan area of France is divided into several provinces and Provence one province in the southeast.

I haven't been to Aix since before Covid BUT at that time the Tourist Information office was excellent. My SIL has been since Covid and she and her travel companions took a day tour they booked thru the TI so I thought it was still going strong. They took a half a day trip to Cassis and wished they had done the full day tour as they did not feel they had enough time. It's about an hour's drive down there so that shoots 2 hours of your 4 hour time frame for a half a day tour.

https://booking.aixenprovencetourism.com/excursions.html

I did a Road Scholar tour that was based in Aix and we did a number of day trips out from Aix so there are lots of interesting things to see.

And re-reading your OP, I'm not sure if you will have a car or if you are going to want to do guided day tours?

You might enjoy reading M.L. Longworth's series of mysteries, all set in Aix. The time is present day and the focus is on the characters, the setting, and solving the crimes, not gory details. I did find that Aix, as portrayed in the books, was much more appealing than the actual Aix that we visited. However, we were only there for the day and it was very hot. We stayed in Saint Didier.

Can I ask why you chose Aix? We're thinking of spending a few weeks in the south of France in January/February and I was thinking of Arles for a week, but Aix sounds nice too...

I visited Aix as a day trip from Avignon.

Lourmarin is an easy trip from Aix. It's a pleasant village with a castle and a market day. Marseille and Cassis are also easy day trips. Cassis is lovely and the hikes to the Calanques are worth it for the views. But I am not sure if the trails will be open in winter due to Mistral.

If you do not mind going over the mountain, northern Luberon villages, Arles, Avignon etc can be visited as day trips, though those will be long day drives. There is also an express bus between Aix and Avignon, if you choose not to drive. There is also a train, but the Aix TGV station is a few miles out of the city where as the bus station is near the city center.

Listen to Elizabeth about spelling. If you enter a misspelled place in your GPS you may not get to where you want to go. You will be staying in Aix-en-Provence. Provence is a province in France. Unlike doing a Google search, a misspelled town won't necessarily pop up with the town you want. (I speak from experience of misstating and misspelling French words. In a French conversation it has caused me much embarrassment. Spelling in French is very important.)
Aix will be a good place for short trips to explore a lot of Provence. Pam has mentioned a few places. The Michelin green guide would be an excellent source for ideas. I hope you will have a car for ease of exploration. Aix is a nice university town to call home.
Have a wonderful time!