One possibility is the Virginia Capital Trail, a paved rail-trail from Richmond to Williamsburg. It's only 52 miles long, so it wouldn't be long enough for 5 days out and back, but the trail's other attributes would work. It's a reasonable driving distance for you, it's a paved trail, the terrain is gentle, and there should be no problem finding accommodations. I haven't biked it yet myself.

https://www.virginiacapitaltrail.org/