As for the antifreeze – make sure you use a non-toxic RV safe antifreeze. The last thing you want to do is pour toxic chemicals down your pipes, then flush them down into the sewer when you leave. I’d say 1 gallon for every 20 gallons of liquid inside your tanks (i.e. if your grey is only 10 gallons full don’t put more than a half gallon of antifreeze). Best of luck, winter RVing is great cause you’re often all by yourself, but you gotta keep those pipes protected.
Track your expenses. I just recently started doing this, and it really puts things in perspective. I use this Google sheet to track all my income and expenses (just go to “File” -> “Make a copy” so you can edit it). Once you see where you’re spending too much, it’s easier to cut back! Plus, it makes you think twice before spending (do I really want to track this?).

28. RVing teaches you to fix things. I hoped I was going to be rich enough to pay a mechanic all the time. That strategy hasn’t worked out for me yet, so now I know how to flush my radiator, fix my generator, check gauges, and a lot of other manly stuff I couldn’t do before. I even recently outfitted our Honda CR-V for proper towing, Dad would be proud.