For warm boots in the morning, all it takes is a minute at night. Take your sleeping bag stuff sack and turn it inside-out. Drop your boots in and pull the drawstring shut. Stick it in the bottom of your sleeping bag overnight.
Some of you have snugly-fitting sleeping bags, so the bottom of the sleeping bag gets real busy with boots, water bottles, camera, etc. I have about six inches of free space at the bottom of my winter sleeping bags, so that's where my stuff goes.