Parking at the TTC will cost you $14, you can valet park at the Poly for $15 plus a couple of dollars tip at drop off and pickup, and leave your car at the Poly for the day, you can then just hop on the monorail after breakfast to the MK.
Well worth the extra few bucks to not have to park at TTC and take the tram to the monorail, it could save you at lease a half hour in the morning and when leaving the MK at the end of your day. Simply take the resort monorail back to the Poly to retrieve your car.
When you get to the MK toll plaza, use the right hand lane and tell the attendant you are going to the Poly, they will wave you thru, proceed in the right hand lane to the first traffic light and turn left onto Seven Seas Dr, Poly entrance is less than a half mile on the right.