Where should you dewinterize?

Thanks all! Seems like everyone does at home and appears you don’t need a whole lot of water to get it done. Now I have one other question....I read another blog warning about making sure your fresh tank is either completely full or completely empty. Basically it warned that you don’t want a half tank while traveling on the road since it could swish around and cause trailer sway. So going back to dewinterizing...am I safe draining the few gallons of water into black and gray tanks and then towing with this until I can dump at first CG of season? From what I gather I’m thinking it’s fine because it’s not a lot of water. I’m thinking the other blog was focusing on the fresh water tank because a half full tank could weight a lot.