This is one of the joys of a mid bath when the galley is on the other side of the aisle. I replumbed our 86 Limited 34' which did in fact have hot and cold under the fresh water tank. The water pump is in the wardrobe down the aisle from the galley. The water heater is in the rear of the trailer as well as city water inlet.
If my trailer was gutted, I might have run new lines along the wall around the rear bedroom. I would want a strong water pump to supply the shower in the bath.
I thought it was unfair Airstream would run plastic plumbing lines under the subfloor and above the fresh tank. Mine developed a leak and I had a major project replumbing in PEX.
I just replumbed my friend's 76 Sovereign
31 foot and we ran plumbing around the rear bath and on up to the curb side galley. No problem with operation. Water heater and city water inlet are on the street side.