How can a group of players make a long rest inside Castle Ravenloft?

@ChrisPerkinsDnD how can a group of players make a long rest inside castle ravenloft? my players are starting to get very weak at cripts.

— NiCk – Dawnfall (@NiCk_Dawnfall) April 10, 2017

Strahd doesn't like his guests to be well-rested. He prefers to keep them on edge. They're doomed. #WOTCstaff https://t.co/Ux7hx4sys8

— Christopher Perkins (@ChrisPerkinsDnD) April 10, 2017