I would suspect its like OKW. When we stayed there a few years back, I'd say the actual travel time was at most 15 minutes, including the other OKW stops.
What varies is the wait time between busses. If you just miss your MK bus, you could be waiting 20 minutes for the next one, then add on your travel time to that.
I hope to figure out the bus route. At OKW, we knew that the lobby was the last stop, so in theory, if we were close enough, we could try and beat the bus to the lobby, if we missed it. If the bus makes a loop and you get a room near the first stop, you might have enough time to get to the last stop before the bus leaves the resort.