Holiday Valley is nice. It skis bigger than it is, and Ellicottville is a lovely little town. BUT........I'm not sure I'd make it a "destination trip". For a weekend, ok, if it's not too far. But Holiday Valley is nothing in comparison to Vermont resorts. VT wins hands down. THAT SAID, the problem is your timing. If it's Prez Day or nothing........find a better option. Prez Day is such a $hit $how pretty much everywhere......pay all that money, travel time, deal with drunken idiots in jeans and camo, just to stand in line for an hour? You're better off staying at home.
We make it a distinct point of going to NY or VT on non-holiday weekends, and it's EMPTY. Gloriously empty. Or Quebec......no such thing as Prez Day there, and Canadian money for you Americans is dirt cheap right now. Good food in Quebec too. Just hop across the border for the southern townships. No need to go all the way up to Tremblant unless you want a real resort experience. Even then, as a Canuck, I'd sooner go to Vermont than Quebec.