I am open to anything if people are in agreement. I know it sounds "generic" but I think the phrase was suggested when the thread was started.
How about something that speaks to their sleeper nature? Something like "I'll see you up there" or "I'll see you at the end of the trail" or "Don't worry, I'll pull you out"
This is just a quick brainstorming. I can probably come up with more.
Mind you, I probably have the most stock WK of the group... LOL