We will be driving back on Jan 2 and must be in Paris on Jan 5. Where should we stop? May be multiple stops...

Welcome to Fodors, cayi4. I've never driven on trips to Spain or France but the title of your post made me look at the distance, and yikes! Other posters almost always emphasize the high cost of renting a car in one country, and dropping it off in another. If you are renting a car, I'd suggest taking instead a train to Bordeaux, then the TGV to Paris from there.

https://www.rome2rio.com/map/Madrid/Bordeaux

If you must drive, I hope others can give you first-hand ideas for stops within your time frame. Just googling, Bilbao is about halfway to Bordeaux. If you Google 'halfway between Bordeaux and Paris' there are several suggestions.

Good luck and please share what you do!

Welcome. Since you mention 'driving back' - does that mean you rented a car in France and drove to Spain? If so you may have to drive 'back'. But otherwise it almost always makes more sense to take the train (or even I dare say fly)

Maybe fill in some of the details.

Since the OP mentions "driving back" this is probably not a one-way rental or maybe not even a rental at all.

Bordeaux is at the halfway mark, and I would be tempted to spend three nights there, not having to worry about driving for two days.

If you prefer villages to city life, then there are clusters of beautiful villages around Perigueux and Brive, though they take you a bit more out of the way.

Some other places I'd be tempted go in the summer might not be so great in cold weather.....

Make two stops, one stop could be somewhere around Bayonne and the other somewhere around Poitiers before Paris. It is safer to drive with two well slept nights instead of one.

Sorry, I don't know how to edit my post, but here are a bit more details. By that date, we will be finishing up a 3 week road trip that started from Paris, going South to Toulouse and then crossing over Andorra to Barcelona, Granada and Madrid (yes, we love to drive). We are trying to find one last stop in Spain (after Madrid) on our way back to Paris that is beautiful, as we've never been in the "país Vasco". Do you have a recommendation of a special place to stop for a day or two before heading back to Paris?

We will be on our way back to Paris from a 3 week road trip and we just want to make one last stop in Spain (after Madrid) before entering France...we've never been to País Vasco and would love to experience it. Do you have a recommended place, more village than city?

Thank you. Yes, two stops would make sense. Maybe one last stop in Spain (after Madrid), and then the last in France prior to getting to Paris. With this in mind, could you recommend where those two places (one inSpain, one in France) could be?

We will be on a 3 week road trip that started in Paris, going down South to Toulouse, then crossing to Andorra and Barcelona. Then after to Granada and Madrid and back towards Paris. We will be leaving Madrid on Jan 2 and just want to know a recommended place to stay in Spain (after Madrid) and one place in France so as to divide the Jan 2-5 timeframe we still have available before returning the car in Paris.

Not the best time to drive in France.
4 and 5 are at the end of the school break, with heavy traffic northbound.
and winter storms are not uncommon at that time of the year (strong winds, heavy rain).

I am being very careful to not mention the obvious but why not use the train? It is a bit like going to a very tall building and insisting on using the stairs but with none of the health benefits.

I'm with those who think we are missing some key bit of information.

Four of the OP''s posts from early this morning were caught up in the moderation filter. They have now been cleared.

I'm a great fan of Bilbao, but would want at least a few days there.

Your trip sounds incredibly rushed to me. You'll have so little time to visit any of the wonderful locations you are planning to see! Are you sure you've allowed yourself enough time in each place?

If OP opts for the train, he/she should not wait too long before booking. Had a quick check on SNCFconnect, seats are going fast.

If you read the OP's subsequent entries after post #5 that apparently were MIA overnight, they explain that the car was rented in Paris so dropping it in Spain and taking the train really isn't practical - not only dropping it in a different country but also changing the drop off location/date could double the cost of the hire.

yes, you are right.
I was just elaborating on the plan to drop the car somewhere in southwest France (Bordeaux, Bayonne), which may save costs (if it is still possible to change the res) compared to dropping it in Mad.
BTW, OP should not forget to advise the rental company he will cross a border (most companies charge for it) and, more important, he will go to Andorra. I am pretty sure that French law now requires to have special gear (tyres, snow chains) in this area at that time of the year

Spain also has different car requirements. Minor things like spare bulbs and glasses.

But I agree why not take the train?

Paris,Barcelona,Madrid,Granada are all on high speed train lines.

If the OP uses the train they could add Seville and still be less rushed. Bonus it'll be cheaper.

Has the OP considered holiday closures? Parking? None of those cities really have a great deal of free parking

The OP already HAS their car and has been driving it in France and Spain . . . and it was rented in Paris. So there are several reasons taking a train isn't on the table..

Two other good places to stay after Madrid could be San Sebastián or Fuenterrabía (Hondarribia). Bilbao is good too.