The Cats are nice this time of year - go for a drive around the Ashokan Resevoir - BTW - do yourself a big favor - stop at the Resevoir Inn (between Rt28 and 28A - on DikeRd/Basin Rd - right where they meet)
You could go up to Phonicia, and Woodstock (which is NOT where the concert was, that was Bethel)
The "Old Rheinbeck Aerodrome" (across the river from Kingston) puts on a nice WWI airshow on weekends - plus get some apples in that whole area
If you want a nice, but expensive place to stay (that I haven't been to in 20 years) - Look up The Whistlewood Inn. A nice B&B
No financial ties to any of this - I just love the area, used to own property up there, have a lot of friends up there, and hope to buy property up there again