'Derm is great and I've had a lot of success with it in the past.
However, since application is an issue, I wouldn't recommend it in this context. I'm 7 sessions deep in my backpiece and haven't had any issues sleeping on the fresh tattoo doing the following:
1) Wash tattoo the before bed after the appt.
2) Re-wrap using saran wrap and medical tape
3) Wear a loose T-shirt overtop
4) Carefully remove in the morning (soak T-shirt in shower and remove there if your wrap-job didn't hold up and some of the tattoo is sticking to the shirt).
5) Wash tattoo and go about your day
After the first night I haven't had much issue with a lot of plasma weeping. Sleeping was pretty "normal" after that. Not saying it's "pillow-soft-comfortable", but it's about as normal as can be the first few days post tattoo. Also, with my backpiece the sessions are almost always more heavily biased to one side of my body than the other, so I've gotten away with sleeping on my less tattooed side, pretty comfortably.