My husband and I just built a night box based on Tom's designs posted on this forum (many thanks, Tom!). I was building for maximum insulation, but my husband is worried that Shelly, our 50 pound sulcata, will suffocate at night when it is all closed up. It is 4 x 4 x 2, insulated and sealed with silicone. The door has about 1/4" clearance all around, and plastic vinyl strips hanging on the inside. I think the door space will let in plenty of fresh air, but my husband thinks the vinyl strips will be too restricting and he wants to drill holes on the side of the box so she can breath. I don't want the precious warm air escaping. Can anyone speak to these concerns? Thanks!