I appreciate everyone's insight.
To clarify a few things, my TT right now is parked at a sorta permanent location; my wooded property in northern Minnesota. Thus I'm well aware of the potential mouse haven I could create, and really had to deal with last year with my covered boat too. That's reality when you choose not to store it elsewhere. But, I am prepared for it.
I also don't plan to use my TT any earlier than when the lakes around here have no more ice upon them. That's to say, the snow and ice will likely be melted upon the TT as well if not before the lakes. So having my TT be mobile during the non-vacation weather I'm not really concerned about.
What I am concerned about is the Cost of a Cover vs. Benefits of a Cover. I also have 2 AC units and some rooftop vents that I feel may not survive having snow blowing directly onto them. I may have a leaky problem come spring, which is what I'm trying to prevent. I know that RV lots keep their product uncovered, outdoors, for the winter. Most of them only keep product for a year before it's someone else's problem anyhow. And Covers, good ones, are at least $300 and PITA to put on without tearing the fabric. So perhaps I just need to cover the AC units and vents? But one of the responses stated that having a cover also keeps the condition of the TT good longer than exposing it to the elements for 6 months of the year. That's true. Which is why I have my boat covered when not in use. Or if I had a classic car, that too, when not driven. So... choices choices choices.
Regarding the jacks and stabilizers... seems like it doesn't matter whether or not they're deployed or stowed while the TT sits there for months on end. And I do have a good hitch lock, not one easily taken off. I've replaced all locks on the TT as well. So perhaps keeping the jacks and stabilizers deployed, and battery removed, is just another theft deterrent.
Any other insight or input is appreciated. Thanks to all those who have responded thus far.