I heard a report of British campgrounds and those in Europe are normally only supplied a 7 amp circuit for the campers over there. I don't know that I would ever want to camp with limited shore power. 30 amps is small enough. Anything smaller, and I would rather be dry camping. . .
Normally I only use the solar power anyway, unless it is warm, and then I will want a 30 amp circuit to run the A/C. The A/C should use about 1,200 watts on a moderate temp day, while it can use upwards of 1,500 watts on a hot day. If the power into it is only 105 volts on a hot day, that can be a little over 15 amps just for the A/C.
HAve fun camping!
Fred.