I stayed in Berkely Springs and drove around Great Cacapon a year or so ago. The side roads in the area may be rideable, hope you enjoy lots of hills and up & down. If you can get to Hancock or Paw Paw, you have the WMRT and the C&O Canal Towpath (bring wider tires for that that one). Very nice this time of year. Bring a flashlight for the C&O PawPaw tunnel. I don’t think there is any safe way to ride from Great Cacapon to Hancock MD – I recall US 522 is very busy, lots of heavy truck traffic, and no decent shoulder. There is a bike shop in Hancock MD that should have current info. If you wanted to do up and back hill climbs without getting anywhere (but a great view at the top!), the roads in Cacapon State Park looked interesting – also lots of ruts & gravel. Bring a ‘cross bike? A quick google search suggests there are off-road trails in the area.
Berkely Springs has day spas with excellent massage session packages – my wife had been there before and had the B&B we stayed at book one for me. I was so relaxed I was ready to be poured off the table into a bucket by the end of the session. Check ahead for days open and availability – the town closes up early and takes early weekdays off out of season.