Solar panel - wild camping

stbiggles

As a complete newbie to motorhoming I would appreciate some input regarding running on solar power when wild camping. We have a new Eldiss 195 with 85W panel fitted (charging both batteries). We have a couple of 3 day wild camps planned next summer. Obviously
most of the facilities will be running from gas, but should we be able to get by for 3 days on the leisure battery and panel? I really have no feel for usage but probably 3 hours lighting per day max plus power for onboard systems.

Any help greatly appreciated.