Family skiing in Provence Alps?

I have not been there, but Isola 2000 appears to be the largest area in the Provence Alps, 90 km north of Nice.
https://www.isola2000.com/en/winter/

I have family in Barcelonnette and, therefore, went skiing many times in the region. I like it a lot!

Pra Loup is the best resort of the bunch, with excellent intermediate terrain and a link to the Allos valley which opens up a LOT of terrain when open (the link is weather-dependent). It is also fairly snow-sure. However, the resort itself is no beauty and I typically stay with my family in Barcelonnette, a mere 6 miles away.

Le Sauze is more charming, very old-school (including slow, tired lifts, partly offset by an $40-45 day pass), but sadly less snow-sure (lower elevation, hardly any snow making).

La Foux d'Allos is linked to Pra Loup, very cheap, but it is very hard to get to (the road is horrible), quite ugly, and the local terrain is limited if you don't venture on the link to Pra Loup.

Never been to Le Seignus.

Two words of warning:
- December is early season when it comes to snow. Some years are excellent (including lately), others are very bad. It reinforces my recommendation for Pra Loup, which has the best snowmaking facilities.
- Getting hold of a rental car with snow chains is near-impossible in Marseille, the nearest airport. You'll need to insist... Or plan some time to buy chains on the way.

As for Mont Serein: you cannot plan a trip around it being open. Snow record is erratic.

I'll throw in another candidate: Serre Chevalier, and specifically the base village of Le Monétier: a very charming village (with a lot of through traffic, but not that intrusive IMO), lively and with great restaurants, with access to top-notch skiing both above and below the treeline, miles of trails for all levels. Really a top-tier resort. Better snow record than all of the above, but higher prices and more crowds to match.

By the way, when you say "family skiing", how old are the kids? If young, then Serre Chevalier isn't that great (walk from village to lifts, learner bases that can be far up the hills).

Thank you to writers for responses--the tip on Isola 2000, and to Balso, for the lengthy and super helpful answer/info about Pra Loup etc. Great intel about amount of snowfall etc-it'll be very late Dec before we get to the mountains. Admit was surprised about comment on chains for tires. I will of course look into further. Wondering about on how much of the drive, say, up from Cote d'Azur to Barcelonnette and up to the ski areas would chains be typically used? We are used to all-weather tires or even snow tires in winter but no use of tire chains in the recent past. Appreciate the help!

A few places in western US require chains when it snows. Donner Pass in California on I-80, US-26 in Oregon by Mt Hood, Little Cottonwood Canyon road to get to Alta and Snowbird, to name a few.

Yes, sam, good point, in the US west of course. Was only writing from our usual experience out east. Different climates, different terrain. Good reminder!

Thanks again Balso for this additional idea: Serre Chevalier, and specifically the base village of Le Monétier tip. Will investigate for sure. As for "family skiing"--actually our child is now a university student--we are all strong intermediate skiers so maybe not a problem.

Now I Am a little hung up on how to safely get north to Barcelonnette area either from Riviera or from Aix area (can organize the trip either way). Glad you raised the road/chains issue for mountain roads. Am aware driving a rental car means twisty mountain pass roads that may close in bad weather or at least be challenging to drive...looking into trains from various directions (or go up from Nice to ski and then back down to Aix?). We are used to snowy road driving in winter in northeast US but not high passes with hairpin turns. Was hoping for flexibility of having a car but hair-raising drive (even if only 3 1/2 hours) would be hard on a holiday....--any advice on that? Thanks again!

Nice / Riviera to Barcelonnette is basically impassable in winter unless you take a long detour: the passes are closed. It would take, maybe 4.5 hours total instead of 3, so not the end of the world, but still annoying.
Of the places mentioned, you could still reach Là Foux d'Allos in 2.5 hours or so.
This said, starting from the Riviera, then Isola 2000 or Auron make for more convenient skiing destinations, but I have never been.

To reach Barcelonnette, starting from Aix-Marseille is easy, chains/snow tires usually not needed, but you never know. My parents had to buy chains (no snow tires on car, rental cars never have them here in France) once at a random village on the road, thankfully the garage was in stock for their wheel size.

To reach Serre Chevalier, from Aix is easy, from Nice is again a long drive (5 hours+). But with a basically adult child, it would be my preference: still very French, but with skiing closer to "world class" in terms of the lift infrastructure and breadth of terrain, and some great accommodation and restaurants in the base resorts (including Le Monêtier).

Such great info, balso, I am indebted. I had had difficulty sorting through the other sources of info on the skiing options as you could see! Am rethinking the order of our itinerary to follow this advice--thrilled to find out about Serre Chevalier. Thx again.

If you have any further questions, feel free to ask either here or by DM.

A broad reply, ignore if you please!

December snowpack anywhere in the Alps is a roll of the dice. And the southern spur of the Alps you intend to visit has far worse chances of reasonable snowpack than the northwestern parts of the range.

If December skiing is a take it or leave part of the trip, fine. If you really want a good chance of a quality ski vacation in the Alps in December, go to Arlberg or Vorarlberg in Austria, just east of Lake Constance. Like Whistler or Mt Baker on the US West Coast, this area draws in early season storm systems that haven't yet sagged south enough for the area you intend to go. And Constance creates some lake effect snow. Lech area is usually good skiing weeks before most other areas have filled in.

Wherever you go hope you score awesome skiing!