I would say 95% of the time you will be much better off with upgrading your wiring to No 8 wires or even No 6. The true reason you would want to do this is only if you don't have solar power, and you like to travel only for a couple hours. Larger wires will feed that engine power to your battery charger (usually a 45 amp per hour charger) and an average day camping will often consume 45 amps. But remaining at the No 12 feeds from your engine, will likely require about three hours driving instead of about one with bigger wires. It's not often that a single alternator would not provide that much power above all other needs.
