I do have a practical suggestion. Don't make it all or nothing. Say maybe "Let's just drive over there and see if you feel differently," or see if he's hungry or doesn't like his shoes or something plain and practical. Maybe he doesn't want to miss a program; can you record it? Maybe he doesn't want to go out in the cold. Maybe if he does get in the car and get there, maybe he'll want to go in. Maybe it's the being at rest that he doesn't want to change.
Maybe you could say "Let's go and watch a while, and then if you want to come home we can." If he gets all the way in and sees the other kids, he might want to stay, or he might not.
The final decision doesn't need to be made before you leave or even after you get there. Every moment can be another "pass or play" point.
Instead of looking at it as a "commitment," think of it as a series of choices.
photo by Sandra Dodd
of Marty Dodd at 9 years old.
He finished the season, but didn't want to return because of the pressure other kids' dads were putting on them to WIN and to be aggressive.