Our shower was configured strangely in the 1930s home we bought- the head and handles were on the shorter end of the wall- we had a plumber move just the shower head to the adjacent wall. Hard to explain without a photo. We also had to replace the old lead shower pan since it was leaking.

Recently the hot/cold was going crazy- no hot water- then scorching- then freezing.

We had our hot water heater replaced ( tankless- super expensive) to learn that it wasn't the hot water -we need a mixing valve type shower.

Should we have a problem with changing to a single handle shower with valve when the head is on the opposite wall. I think it may be an issue? If we can make it happen - are there recommendations? The plumbing in this old house is driving us crazy. Nothing seems to work properly. Water pressure is awful. Have been told we need to expand our water feed- which would require digging out Lord knows What or how deep to get down to where the water comes in. It all looks awfully expensive!