It was pretty funny back in the day (Green Acres TV show, for those youngsters not in the know). Now it's not so funny, having to run an electric van on 30A, as we found out the first night out when the shore power CB blew while cooking and we ran out of heat at 4:00 am, since it was running on battery power.
Shoulda used gas for heat, at least until bed time when no other loads were on.
Gottta invest in an ammeter, or remote display for the inverter/charger, since all the shore power goes through that.
And of course, running a 12kW coach on 2.4kW, or even 1.8kW of shore power would be a real challenge, but with the appropriate mind set, should be doable.