I can help with this!
We ski every year (5 weeks this year in fact; 1 week Whistler, 1 week heli-skiing, 3 weeks Chamonix).
We LOVE Whistler. It is immense for sheer scale and variety. Yes, it is a long way, but conditions can be unbeatable. There is more than enough skiing for all ability levels to fill several weeks, and that's just the on-piste stuff.
It certainly ticks your boxes for everything you need in one place. Loads of options of places to stay, eat, shop, rent gear etc. And actually not silly expensive if you book early lift passes and get yourself organised, which it sounds like you already are doing.
If you don't want it bitterly cold, I'd recommend March before it gets mild. After Feb half term and before Easter when the schools have gone back is usually a good time for quieter slopes. We were there in jan and it was -24c, the peak was closed etc. Damn cold sat on a chair!
I also personally recommend Nita Lake Lodge, having stayed in several places in the area. Rooms are all suites and can be had for around £100p/n, a veritable bargain. Still walkable to lifts, and next to a truly brilliant little restaurant (2 week waiting list for a table in winter!). Creekside is that little bit quieter than the Village, but free hourly shuttles in to town for eats, drinks, shops etc at your leisure. Welcome to PM if you need any tips.