Hide size VS snake size

Hello. I have a year old ball python. It seems to me that her half circle bark piece is getting small. I'm looking to transition into a bioactive enclosure and it needs a depth of 3-4 inches and I cant have the heat matt at the bottom (per instructions from the BioDude) I'm struggling to find a decent size hide to house her but also allow her to create her own burrow. I was wondering if anyone has had any luck with this issue before? Doing this on a mobile and not sure how to upload a photo of my set up