Wine bottle protector

My friend has this weird case for a wine bottle. It's intended to protect and keep cool a bottle of wine while hiking. It's an insulating fabric/foam case on the outside, and used to have a rigid plastic hollow tube with freezer gel inside. That inner tube was cracked or lost, and he asked me to design a replacement.

He didn't care about cooling the wine, but wanted shock protection for the bottom portion of the bottle. He gave me rough measurements of the old one, and here we are.

Included is a tester piece with just two springy living hinges for dialing in settings before you commit to the entire diameter. I'm not sure if this is going to be widely helpful without protection for the neck, but you never know!