I believe they give you 3 hours officially to park at any resort to eat or whatever. Since you have a parking pass already for your hotel, you can easily get in and park.
The only question would be how long you plan to stay there, or if you are going to MK before or after. I did read that they err on the side of caution before towing a guests car and some have stayed parked there all day. If you are nervous about it, I would park at TTC and take the monoral or walk over to Poly. It would be faster than the busses!
Have fun.