I have a total 110’ run from breaker to trailer using 10 gauge solid wire and the trailer’s 10 gauge cord set.
There is usually 120-122 volts with small loads and a 4 volt drop with the a/c running. I only tested the a/c once and didn’t see the initial drop as the a/c started. I have no need to run the a/c in the trailer at home as I don’t have any a/c in the house.
I have an EMS, so I really don’t worry too much about voltage drops.
I would not run any less than 30 gauge that far unless you are just going to have a small (10 A or so) load.
