We've done butts in 4 hours flat at comps at temps around 315-320.
I'd get them all in the oven or crank the temps up on the WSM's to above 300. If they're foiled, they'll be somewhat protected from the extra smoke.
At 170, they should probably out of the stall, so crank em up and they'll get there pretty fast.
Another thought: How far away is the place where you're serving? Is it at all possible to start serving whatever's done and let the others keep cooking if needed and run back for them? I know it's not ideal, but????? You may end up with 1/2 of them tender in an hour from now. I know what you're feeling man.......and is sucks. I've been there.
18.5", 22.5" OTS
Large BGE (chambersuac's)
The Fiery Furnace (chambersuac's)
Big JT's Smokin' BBQ Competition Team