I would try to get that well done, and then ask the local govt if you can set a septic tank, even without a drainfield. You could use it as a holding tank between honey dipper visits if the ground freeze wont cause too many problems.
If all else fails, get a macerator and fill tanks on a truck or trailer and dump at that friends station.
Dont know how large a trailer you are looking at, but some modest sized ones do have decent tank sizes, some 29' Rockwood and Flagstaff models for example have 45 gal black and 90 gallon grey, At least they would buy you a little time between shuttle runs.