Looks like a very useful rig for the conditions you hunt.

As for a muzzle cover, when hunting elk in Colorado I have always used a small balloon stretched over the muzzle. You can buy a bag of 100 for very little. It's effective and doesn't change point of impact, as far as I could tell.

Here I am in 1992 the day before the season ready to hike in for the night and set up a little spike camp. You can see pink balloons on muzzle of each rifle.

Curl