We lived in our 27' RK 5th wheel trailer for one winter (7 months) with temps down to zero while the house was being built. I had water/30 amp electric set and a 3" sewer connection to my home septic tank.
I don't remember brands or prices as its been 17 years ago. I bought my own heat tape with a thermostat for the 10'-12' water hose. I wrapped the hose with two layers of 1/2" thick fiberglass insulation with a foil backing then added a 1" thick water noodle over it. I then used duct tape from top to bottom to seal out rain. No issues.
This unit had two drain points. A black and grey in front for the bath room and a grey aft behind the wheels under the rear kitchen. I ran 3" pvc pipe angled down to the sewer connection about 8'-10' aft of rear of the trailer. I bought everything from a plumbing/electric supply.
The most expensive part was mobilehome skirting. This did more than anything to keep the cold out.
Draining three tanks was no problem even in subfreezing temps. A single mobilehome skirting panel is easily removed.
I pulled the black tank valve first/then the grey next to it/then the other grey. I had lots of down drain angle so water never froze. Plus in this country it may get to zero but three days later it may be 60 degrees with lots of sunshine ......heating exposed pipes.
I had the 3" rv drain line put in when my sub contractor put the home septic in.
I ran the 110 electric underground for about 175' myself from the the service pole. I also ran about 200' of 1" pvc water line from the well house to a freeze proof hydrant behind the trailer. The wife and I did every thing. No issues with drain or water hose.
