You can get free parking if you are willing to arrive around 6:30am for park opening. DH and I do this every time we go (we are annual passholder so would get parking for free anyways). We like to do this at DHS parking lot for our DHS and Epcot days. We arrive around 6:30am walk over to the boardwalk bakery to grab breakfast and relax enjoying the boardwalk in the morning. After that we walk to to DHS or Epcot about an hour before opening and get a front of the line spot.
For our MK day we arrive same time around 6:30am and park at the TTC. We then walk over to the Poly and enjoy breakfast there. An hour before park opening we take the boat or monorail from the Poly over to the MK.
The only park we haven't done early is AK cause we usually do that on our arrival day so we are never in Florida early enough.