Andy this weather patern it is difficult to predict. Somethimes Belleayre will get Snow when Hunter/Windham does not and sometimes its the other way around. Belleayre and Plattekill will get Lake Ontario lake effect snow squalls where the others don't.
I like your plan of skiing Hunter Sunday. Satruday the crowd at Hunter "may" be a ZOO on that single opened trail. Belleayre the trail that is opened is shorter than Windham. But Belleayre will be in better condition snow making wise and will have significantly less people on the trails. Belleayre has been more agressive in the snow making department in recent years. Then again Windham just spent some more money on snowmaking and they want to prove a point. All 3 mountains have a little something different to offer. Sounds like Windham may offer night skiing which is something you might like.
If you like long wide groomers with few skiers to get in your way you should come back later in the season and try Dot Nebel trail at Belleayre.
Note that Windham is 7 miles away from Hunter. Belleayre is about 20 minutes awas from both Hunter and Windham. Belleayre is a about 15 minutes closer to the DC area than Windham and Hunter.
Windham has the best upscale hotels to stay in.
Belleayre Motels click here
. Econmical try Starlite Motel. Ulitmate high end try the Lodge at Emerson PLace (Catskill Corners). For a nice B&B next to Belleayre Ski area try the Alpine Osteria
. Also the Colonial in Pine Hill has a great all you can eat Buffet with crab legs.