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.

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