The route planning http://www.autoroutes.fr/ suggests 7 hours and 35 minutes from Calais, to Lyon, via Reims (with a caravan), but that's without stops, and driving at the maximum speed limits. It's always adviseable to add extra time to this, it's surprising how much time it takes for the odd 'comfort' stops!
The total tolls from Calais to Perpignan on the Reims/Lyon route, with a caravan are a massive 144.20 euros EACH WAY (94 euros without the caravan) and the length of the journey is 1212 kilometres.
If you go the alternative and shorter way, suggested by David, via Rouen and Clermont Ferrand then the tolls reduce to 70 euros each way. The journey length is reduced slightly to 1143 kilometres.