I think six sets of warmup (for your 11 sets) are a bit too many. Three should be enough, and you don't need a real break between warmup sets. That should help cut down. Mehdi even recommends skipping breaks when switching exercises. Indeed, with 1.4 BW it will be tough. But that's what deweighs are for, and at that level, you'll be going into 3x5 soon.

Stronglifts is amazingly high impact for the time it takes.