We live in a Condo and have not found it to be an issue. Don't over think it.
Everything stays in the trailer except for clothes, towels and bedding which need to be laundered anyway. For groceries, we stop at a store on the way out of town and pick up what we need.
We got lucky? and found a place that with indoor storage that pulls out the TT and has it waiting for us when we request it. When done, just drop it off and they put it away. It has facilities that allow me to do maintenance like lubing axles, washing/waxing and such for $50 mo. That is the min. charge so a larger TT may cost more per mo.
I would rather have it stored off site indoors than on my property out side in the elements. That is what is hardest on a unit long term IMO.