I use an okay tent and a good sleeping bag. Setup tent where there are natural wind breaks around and I personally go for a little off level. This help get the water off the tent when snow/ice melts. Also, dig drainage around tent.
Get sleeping mat(s) to lift yourself off the ground. Eat right for metabolism, keep hydrated and drink warm stuff in the morn. Dress in layers...etc. Either way, come crap time your screwed baring your ass in the wind and cold - but you'll warm up.
IMO 0 degrees is one thing, 0 degrees in 10 mph and high winds is totally different. Stop the wind the best you can and you'll be happier.