Our stay at the Hotel de Glace was amazing and I would highly recommend it to anyone considering it. No, we were not cold :) All beds have a thick memory foam mattress. In addition, there is a constant temp in the Hotel de Glace (HdG) and the sleeping bags are rated far below that temp. It's a great one-of-a-kind experience.
After reading other reviews, I believe they changed the room policy for 2020. From the previous reviews, it sounded as if guests where given access to luggage storage lockers, communal showers and bathrooms. That was not our experience.
We booked a room in the HdG through Hotels.com, but were also given a nice room in the Hotel Valcartier (the property where the Hotel de Glace resides). So, you’ll have 2 rooms – one in the HdG to experience and the other to store luggage, bathe, hang out and, if needed in the middle of the night, could come back and sleep in conventional bed (which won't be needed, but it’s nice to know it’s there). You have to be out of the HdG room by 9am but you'll have the Valcartier room until 11.
I added some pics but it will look different each year, as it's built from the ground up yearly. We would highly recommend the experience.