My solution now is to head south also :B, but when I lived in -40f winters I would blow/pink stuff/blow again. I was always amazed at how much clear water came out prior to the pink after that last blow. Happened both for my MH and 5'ver.
Last fall I helped my northern neighbor winterize his new TT. I did the blow, pink, then blow again. His new rig didn't have one drop of clear water coming out prior to the pink after the last blow. I guess it depends on the RV.
I also catch the pink stuff then use it in all the traps and toilet. At -40f the pink in the toilet would freeze, but it was a "soft" freeze and could be easily whittled with a jackknife.