Sleeping bag best practices in cold weather?

[DanJT]

Not sure if I titled this correctly, but here is my question: should a sleeping bag when used in cold weather be tight or loose?

 

[Jeep4Life]

I think that is going to be a personal preference thing. I like to have a little room around me, so mine isn't tight, but allows me some moving space.

 

[Dirt Dude]

I need space, if it's tight, I would get claustrophobic