I thought I saw something about a jogging path when there in Aug. I thought it was kind of weird since it's so isolated. Don't know how long it is, but you might be able to take a couple laps.
Also, you could take the monorail to TTC and get off there, walk to the Poly and around the grounds and continue on to GF. You'd have to get on the monorail one stop to MK and then get off again and continue back to BLT. I know that's silly because you get on the monorail, but still a thought.
Also there was a sidewalk at the light between BLT and MK. You're probably not supposed to go back there (toward CM parking, I assume), but you could go as far as you're comfortable and your mileage would increase.
Boats to/from FW and WL seemed slightly unpredictable and I would be afraid of being stuck there when I was done. Nothing like a 3 mile walk turning into a 2 hour transportation adventure.