If you really only move 2 times per year your best option (IMHO) is an open face antenna mounted on a tripod like you would find at TV4RV. Yes, it takes 20 minutes or so to setup but you only have to do it twice per year. No one is going to steal it as it has very little value and you will get the very best service available no matter the weather. It's the same antenna mounted on a house so it's as good as it gets.
It also gives you the option of installing a DVR unit so you can join us "time shifters" where we (you) watch what you want when you want vs. being tied to being home at the exact moment a show you would like to watch comes on.
There is NO downside to this type of antenna setup while there are downsides of some kind to any portable dome style antenna.