There have been a lot of people here with the 6R60/80 transmissions that had shift issues fixed with transmission fluid service and resetting the learned data. Some have fixed issues with just a reset only. I have seen very few failures reported here over the years requiring a rebuild or new transmission for the 6R60/80 transmissions. This, and the reliability of the 4.6L 3V engines, is the main reason I replaced my 2002 Explorer with a 4th gen V8. Since you live in Ontario, if you can keep rust in check by yearly Fall applications of Fluid Film, or a similar oil based rust preventative, along with good preventative maintenance, your Explorer should last you for many years and/or kilometers to come.
One thing I notice with my Mountaineer is that when my wife takes it on longer trips to keep the miles off her Edge, the transmission has a few minor glitches afterward when I drive it. I know her driving habits are much different than mine. She drives more aggressively by faster acceleration from a start, and otherwise, along with quicker stops. I think this slightly changes the learned memory and it takes a while to readjust to my driving style.