First off, almost all solar panels will only produce enough electricity to keep a charged battery charged up, but not to re-charge a run down battery.
Second thing, solar panels are big and expensive. Unless you are willing to spend some serious money on panels that will set out on stands pointing at the sun and storing them when you are not there, forget that option.
Third. I'd suggest what most people who dry camp a lot do. Buy a Honda or Yamaha "quiet" generator and charge your battery(s) for an hour or so in the morning and evening.
Go9ing off topic here, but if you plan to do a lot of dry camping, consider switching to two 6 volt deep cycle batteries if your rig doesn't already have them. They work much better than 12 volt batteries, even if they are marked "deep cycle".