There is a hotel in Banchory called the Raemoir House Hotel. That is a nice old country house with a helipad on the lawn - Bit of an interesting approach for my tastes but who says helicopter landing areas and tall trees shouldn't go together ??
Banchory is about 20 miles from city centre. Apart from Ardoe House mentioned above and possbly Pittodrie House Hotel (near Inverurie) a similar distance (20 miles) from town, I can't think of anywhere else.