You can add a Winter/water additive to the fuel but there should be nothing else necessary.
It is also not necessary to run the genset or the coach for the entire Winter season. Just let it sit and start it up in the Spring. You won't do any harm as long as you run the genset under load and actually drive the coach long enough for everything to come up to temp, it's just not necessary.
What I post is my 2 cents and nothing more. Please don't read anything into my post that's not there. If you disagree, that's OK.
Can't we all just get along?