I'm not sure how far the MSP wheelchair/golf cart will go, but if they'll bring you to the bus stop or close to it, the rest of the journey should be doable. I've never measured it, but the 54 bus stops closer than the light rail to the ticket counter, and it should be a relatively easy walk with escalators/elevators available as needed.
The walk from the security exit to either the light rail or bus stop is more than 200 feet, though, and it'd probably be more than 200 feet from security checkpoint/security exit to the gate as well. (Although if you need something that has less than 200' of walking inside the terminal, the only ones would maybe be the very small airports with just one or two gates. Any airport with more than a couple of gates would require more than 200' of walking unless you ask for wheelchair assistance.)