Only suggestion might be riding up the wye valley between Chepstow and Monmouth. Tintern abbey is really worth a trip, there are some stunning swimming spots in the wye and lovely pubs. I don't know the cross country route you've drawn via Usk because I'd always go via the wye (or the road on the ridge to the west of the valley) and whilst it may well be nice I bet it has less massive ruined abbeys or charming swim spots 🤣. Monmouth to Aber is a nice road too...
Only suggestion might be riding up the wye valley between Chepstow and Monmouth. Tintern abbey is really worth a trip, there are some stunning swimming spots in the wye and lovely pubs. I don't know the cross country route you've drawn via Usk because I'd always go via the wye (or the road on the ridge to the west of the valley) and whilst it may well be nice I bet it has less massive ruined abbeys or charming swim spots 🤣. Monmouth to Aber is a nice road too...