The western maine border with NH (bethel area and Gorham NH) may be worth checking out, the Bethel/Newry area has hotels, dining and lots of outdoor options beyond Sunday River resort itself. Mt Washington is an easy drive away, access to AT trails and parks etc, and Bethel is pretty decent for tourist amenities and has cool one-off resources like the Maine Mineral & Gem Museum which is awesome to check out

And bethel got a good dump of snow this week as well