There is a custom builder called Space Craft RV. They build towables but might build a drivable.
Most of their recent builds incorporate LG Mini Split heat and air units, heated floors, normal size appliances, etc. Several I know of run off battery entirely. 4-4k Magnum inverters pulling off of a variety of battery sources. Either Volt batteries, Telsa, or a company called Volta. Entirely custom builds. Your wife want a large tub? Done. Nothing but solar on the roof? Done. Heated floors, silent mini split temp controls? Easy. Tired of sweeping and vacuuming and want a Roomba? Simple with toe kick storage garage of course. All tablet operated? Easy Peasy.
BUT... Bring your check book.
They are on FB with recent builds.