On our 41, we’ve been living aboard for 3-1/2 years now on a single 30a without issue, but we’re minimalists when it comes to electricity. No A/C, thanks to mild SoCal coastal weather in the summer. Winter heat is provided by low draw Caframo space heaters, usually just one at a time, sweaters, an extra comforter & body heat
Just boils down to needs/expectations I guess. The RW35 we are rebuilding has (had) 2 Cruisair A/C units, each with its own 30a 120v shore power inlet, plus a separate house 30a inlet…the wiring is (was) a nightmare.
Those A/C units are (were) responsible for 5 extra holes in the hull as well.