One way to somewhat alleviate that is to pay for preferred parking. When you get to the P-Lot gate, just ask the CM for preferred parking and you'll only pay the difference between standard parking (which you get free as a resort guest) and the preferred rate (the difference being $15 if I'm not mistaken). At MK it's huge savings in walking distance, maybe slightly less depending on arrival time at Epcot, HS, and AK. At MK, the preferred parking lot is really close to the tunnel under Seven Seas Drive, so it's maybe a 5 minute walk to the TTC.