My new revised weather isolation technique which shall be named "Breakfast Bag" finally reached its ultimate form. You can only hardly distinguish it from a non-isolated 135L.
Spiffy idea. But be sure not to store your lens like that. The plastic will prevent any humidity & condensation trapped in there from drying out, which could lead to rust, fungus, etc. over time. Especially if you go from cold winter outdoors to a hot humid place like a crowded restaurant, it'll probably be kinda soggy inside if you don't leave the camera in the bag & let it warm up gradually over time.