Scuse me while I go pop some popcorn
OK, I'm back, fun reading for sure.
Here is what I have done. I have a 30 amp service and had a 15 amp converter plug plugged into 12 ga extension cords, a 25' and a 50'. Worked good the first year, could run everything including AC off it. Second year my voltage line conditioner kept tripping. I discovered the conductors in the cord had corroded, causing a voltage drop.
I went and bought a 100' roll of outdoor heavy duty 10/3 cable and two 30 Amp fittings, along with a 30 Amp outlet, breaker and wiring. Since I run the feed from my barn, it was easy to run the outlet to a place near the door. Now I can run the entire trailer off the 30 Amp service as if I were in an RV park.
If the OP can't run the outlet, at the very least make a 100' outdoor 30 amp cord. Use the adapter at the end of it. Most important though, KEEP the connection OFF the ground!