I am looking for an approximately 0 to 15 Fahrenheit rated down bag for a project. It should be either a wide foot box (preferred) short/long bag, or a narrow foot box long bag.

I will be using it as an elephants foot while sitting in a tree stand with my boots on. (Hence the need for a wide foot box). A narrow foot box would work, but I will be chopping it at the knees so it is wide where my feet are. Would like to come up to my armpits approximately and will add a cinch and chop the mummy hood off. Let me know if you have anything that might be suitable. Thank you.