First all let me say, different folk feel the cold differently. So what might be comfortable for one may not be for another. With that in mind, if I were you I’d start close to home or your car and have a trial run before committing to the hills.
Personally, I use a mountain tent (without valences). The aluminium poles along are good enough to keep the tent up in all but the strongest winds, only then do I need a guy line or two. What is important, is to keep the wind outside. Use anything you have to block or cover the gap between the fly and the ground, at least on the windward side (wind can shift direction in the night), I’ve even used snow to do this before now. I can’t overstate this point, it’s worth the time taken to get it right. The next thing to pay attention to is the ground, you must be well insulated from it. Weather its two roll mats an air-bed, air-bed plus roll mat or just cardboard and newspapers this is the second biggest factor in staying warm. Then there’s the sleeping bag, tricky this one, because as I said at the beginning, everybody’s different. But if you’ve got those first two things right the sleeping bag will be easier to control. It must allow you to ‘breathe’ and not sweat, if you do sweat it has the potential to make you colder. A little trial and error should get this balance right, I find sleeping in the buff preferable to wearing clothes, yes I’m actually warmer that way, remember if your feet are cold wear a hat. Don’t miss your evening meal. Never go to bed wet. That should be enough to start you off topher, best of luck