Do what you can to block any/all wind from blowing across you where you will be sleeping. Even a slight ... breeze ... still cools you down a lot.
A silk scarf! It is amazing how good they are wrapped around your neck! Especially when just working/setting around camp.
When you wake up in the middle of the night and feel that ... urge ... to answer nature's call, just do it. Don't fight that urge and try to get back to sleep. Just grit your teeth, get up and do it. Fighting the urge is worse than getting out in the cold and having to warm back up. Plus, it gives you the chance to tend the fire.
Have a little "high energy" snack to munch when you do wake up in the middle of the night. A mini chocolate bar works wonders. Or a handfull of peanuts/granola. This "fuels" your body - after that evening meal, but before morning revelry and chow.
Then all those other tips already mentioned: wear a hat - especially at night sleeping; drink more water than you think you want; don't skimp on the TOTAL CALORIES consumed during the day; multiple layers of clothing; dry clothes at night; etc.
And try not to HAVE TO rely upon that fire to survive the night! That's pushing things a bit far. It often shifts to you sitting up huddled around feeding the fire all night!
Earplugs! Unless you are used to the snoring from your buddies near by. Or their moaning/complaining about the cold!
Adult beverages only in small quantities. Go for a quality experience instead of consuming "mass quantities".
Or, one of the better "tips": bring a good "sleeping bag" along -- if she's willing to go along! Two people sharing a bedroll makes it much warmer and more comfortable. Well, at least until ONE person hogs all the blankets!
Clunk ... Bang ... Thunk ... oooh ... ouch ... enough with the sticks-n-stones! I'll behave!
Just a few humble thoughts to share. Take them as such.
Mikey - that grumpy ol' German blacksmith out in the Hinterlands
p.s. And nothing prepares you for pulling on those COLD shoes/boots/mocs in the morning just before dawn! Even when you know they are going to be COLD! Especially when you brush FROST off of them!!!!! (You can put them inside your bag with you, but they tend to be ... cold and lumpy to sleep with.)