Firstly enjoy – Honfleur is lovely, beaches at Trouville and Deauville are very nice too.
I’d say probably road, we were in the area a few weeks ago and noted quite a few marked vtt routes in “Suisse Normandy” which is inland a bit from where you’ll be. I have to say I’ve never been able to find a directory online of these vtt routes. Aside from that I think you’ll just have to buy an IGN map and follow your nose.
You can do a little research via this site (once you load a route you can switch the maps to IGN and then scroll around – my experience is you can ride on the paths / trails without any issues and the marked vtt routes I’ve ridden with Trail Addiction – Dest-X and also around Les Gets/Samoens have been on the paths shown on IGN maps)
utawaga vtt