I'm confused because your two posts sort of contradict
Your first question is, can you activate a
UT ticket at a Disney resort hotel.
Even without a MB, yes you could get a plastic card at a Disney hotel to use for ticket access
But
then you say you are staying off property
So there lies my confusion. Why are you asking about activating at a Disney hotel? You are not at a Disney hotel
A Disney hotel will not give you a plastic card for ticket access if you are not a guest
As someone staying offsite you will have to go to GS to get a plastic card ticket if you do not want to use your phone as your ticket