Not sure whether or not you are aware of this, but there are already companies that make sleeping bags with integrated sleeping pad sleeves. I think Big Agnes w

Not sure whether or not you are aware of this, but there are already companies that make sleeping bags with integrated sleeping pad sleeves. I think Big Agnes was the first and they've been doing it for over a decade: https://www.bigagnes.com/Products/SleepingBags https://www.bigagnes.com/Products/SleepingBags