I'm not so sure. The bar will be set pretty low, so all he needs to do is show up and not trip and fall on stage and he will be deemed the winner.
The media might declare him the winner but people will see what really took place. There is a real possibility he freezes in the middle of the debate.
I'm questioning if the democrats might be pressuring him to do debates knowing he will flop. This would be before the convention and they could use his performance as an excuse to replace him. There would be little time to dig up dirt on whoever replaces him before the election.