If it's not too cold you could probably get by with just blowing out the water lines with compressed air and draining the water heater, rather than putting the pink stuff through the lines and dealing with dewinterizing multiple times a year. That's all I do as I go up to norther WV for hunting season where it gets to single digits consistently. Sometimes below zero, but not as much these days.
As far as musty smells, I use the Damp Rid containers with the big tablet. They tend to last about 3-4 weeks before the tablet disintegrates and needs to be replaced. I put 3 or 4 in the rig when in storage for a month or more.
https://www.amazon.com/DAMPRID-Conta...s%2C276&sr=8-7
I actually found the replacement tabs cheaper at our local Lowe's than on Amazon. I keep a pretty good stock of them in the rig.
You might also consider how reliable power is where you store the rig. Any heaters, fans, etc. may not help if power goes out for long periods.