Blackwater SP, WV...assuming snow is good. We didn't have enough. Nice area, great cabins.
Is Prospect Mountain that much further than Lapland Lake? Pretty sure accommodation around Woodford is pretty affordable. Snow is very reliable.
Fahnstock? Supposedly Gore Mt. also has skiing, since they're hosting the U16 champs this year. Somewhere in the vicinity of Glens Falls.
Osceola, on the Tug Hill. Lots of snow but questionable grooming.
Notchview, in western MA. Cheap housing nearby. Currently snowy.
Dunno about anything further south, because I usually go north, not south, to ski.
Good point about Prospect Mt. It's about the same distance from us as Lapland Lake, though one could go to Lapland Lake by avoiding I-95, which is a bonus.
Ottawa is a bit further, but has an 8K long skating rink with sleds for Inara. Skiing in the Gatineau is some of best in N.A.
Laurel Ridge may not be all that exciting, but it's a nice little place, and relatively close. We & some QOC families have gone up there a couple times. Good enough to have a full weekend of skiing, though with some repetition.
White Grass is okay, but you have to start out with a big long hill. Nice stuff up at the top, and of course a long downhill at the end (lots of hairpin turns). The cafe, though, is awesome.
My heart belongs to Ottawa.