It's not just the OT, and it's not just about this series.
Rempe had 4 shifts all game. I'm sorry, but that's just not sustainable because the players who are eating those minutes are the top players (Panarin, Tro, Zib) and if you have an opportunity to keep them fresh early, you should take it because we'll need them later.
If you're going to dress him, play him, otherwise what's the point of dressing him? If you don't think you can play him and trust the outcome, then you shouldn't be dressing him.