This time of year hard to say what will be open and what isn't that said loads of wilding spots. Argeles Sur Mer , Collioure( beautiful village) all possibilities little further north some good spots on the Canal du Midi .
I would steer clear of Perpignan it has a bit of a reputation
I lived in Beziers for 12 months be prepared for it to be cold -1 in the morning 7.30 am ish not uncommon, however by mid morning t shirt weather !!!
Spanish side I can't really help with, but the French side you won't have any issues.
Channa