I think that Thor is going to use stormbreaker to get Tony and nebula to earth. Antman and Hawkeye rejoin the avengers when they lose their families to the snap. Iron man and Bruce work together to modify b.a.r.f. to trick thanos into thinking he's won. Thor opens the bifrost to wherever thanos went and the avengers and capt marvel attack. Antman who has the b.a.r.f. is the hero who actually activates it stopping thanos. Captain America uses the gauntlet to undo the snap.

One or more of the main players are gonna die.

Fury's pager sent a message to Captain Marvel in the past. She sets things up so that Infinity War goes better for the heroes.

I think the ones that are left are going to sacrifice themselves for the ones that got dusted, thus bringing "balance" again. No way the dead ones stay dead.