I agree! The self-parking at GF is horrible. I have dropped off my DD and DM and then parked and walked it myself. But if I have time, and aren't running late, I prefer to park at the TTC and ride the monorail over.
Depending on what time you are visiting, you may even get to park close at the TTC. I have parked fairly close when we have done this in the evening.
Besides, riding the monorail is fun!
Of the 3 monorail resorts, GF has the worst self parking, Poly guards can be the most careful about letting you park there, and the guards and parking lot at Contempo are wonderful!
I have never been told I can't park at any of the resorts. I've never parked there and gone to MK though and I know that's a problem, especially at Poly. Whenever we go there to eat all I've had to do is tell them I am eating there. Either in one of the TS (sometimes the guard at Poly will check a list) or at their food courts. Sometimes the guard at Poly will ask you to drive away slowly so they can write down your lic. plate. I think they give you 2 hours parking since their lot is fairly small.
Happy Dining!