Way to go for providing a great and loving home for ClydeSounds like you are a wonderful owner for his forever home.
You can buy moss to increase the humidity and just keep wetting it once it dries out, especially nice to have when they are in shed. I'm not sure which substrate you're using but when we had a screen lid tank I switched to expanding coco-husk and it retained moisture fairly well but I didn't love when it dried out it became a bit dusty. Now I use repti-bark and it seems to keep a nice consistent humidity, looks and smells good, easy to clean out. We recently added a huge water dish for the winter just to keep humidity up. Luckily the winter is almost over and it will be perfect conditions once again since I live in a humid part of the earth.
Hope the shed comes off clean!! Gosh they are so beautiful coming off a fresh shed <3