The average time, from gate to resort, is running about 80 mins. Here's a breakdown of length's of time...
gate to DME area....15-25 mins
getting to bus line....5 mins
wait in bus line......5-25 mins
wait on bus....5-25 mins
ride to resorts.....30-50 mins..depending on which stop you are.
I have made it to my resort in 55 mins...once. I was among the first off the plane, I got on the tram just as the doors were closing, walked quickly over and down to DME checkin....was sent directly to the bus line, and got on the bus. I was among the last to board the bus, and it left after a 2 min wait. Then, my resort, Pop, was the first stop.
The time it took the longest??? Again, at Pop, and it was a 90 min ordeal. The bus line was long, 20+ mins, (the bus to Pop was just pulling away as I got there!!), then a ton of guests had luggage to load underneath the bus..had to be about 30+ people doing that. We sat on the bus for about 20 mins. Then, we went to two other resorts first and had to unload all that luggage!! Took forever!! When the bus got to Pop, I flew off that bus!!!
There is really no way to be absolutely 100% sure of how long it will take you. Plan on 90 mins and you'll most likely be pleasantly surprised when it takes less time.