I put it under my feet as i only carry a 3/4 sleeping pad
If you have back problem put the pack in your tent under your legs. This helps take the pressure off your lower back and it works wonders.
Transcend the Bull$hit
I have the same tent & mine pack is nearly empty when I retire for the night so I always put it in my vestibule, if it's windy I'll lean it up against my head area & use it as an extra wind block. You're gonna want it near you so on those rainy mornings you won't have to go retrieve your pack, you'll just pack everything up & be ready to go except for the tent itself.
Take Time to Watch the Trees Dance with The Wind........Then Join In........
I usually put my pack in the vestibule. I like the idea of using it as a pillow though. May try that the next trip. So I guess everybody hangs their cookset and stove with their food bag? Never done that. I actually don't hang my food all that often. Never had a problem except when I hung it in the shelter and mice were trying to jump on the bag from the rafters! That was fun.
When tenting I've always left my pack outside, covered with a rain cover.