Gah.. DPM etc...
It's all about layers.. so first get yourself some thermal t shirts and long johns, thermal socks as well, 2 thinner pairs are better than 1 thick pair, next a warm t shirt, fleecy is good, the ex army polo neck ones are crackers.
combats for the bottom half, not tight though, warm jumper, fleece, outer jacket, gortex is best and fleece or quilt lined, with a lined hood, same for over trousers, you can pick up realtree gear most places now, much better than DPM and can tailor the camo to where you go ie advantage timber, mossy oak, grasslands etc designs.
Not too much of a problem as in the hide I do put layers on and wear hats, gloves etc, just trying to get the best possible stuff to keep me nice and toastie. Got good Ice breaker thermals, ski socks (not the fleecy ones the proper ones) Thinking of investing in Snug Pack outer layers just to be covered.
Boots, good thermal ones for winter, or ordinary wear ones, field boots are the best..
Gloves are a must as is a beanie hat or for the really cold weather one of the russian fur hats with the ear flaps.
Finally if your going out in the hide get a cheap fishing unhooking mat to put under your feet, it helps keep the cold out and invest in a couple of large stainless food flasks from argos, one full of hot tea/coffee/chocolate, the other with bangers and beans, soup or even the wifes stew and dumplings..oh and keep spare batteries in a pocket near your body in really cold weather..and take plenty.. they don't like the cold.
That's not a problem as got fcilities to make drinks with small burner and can also have warm food, so got that one covered.
*edit*
Just been checking back on what I used to wear, same as above except, fleecy joggers under the combats and a two piece sundridge bib n brace/jacket combo.. been out fishing in that in the winter at night where I was literally covered in frost!! and still nice and toasty on the inside