I suspect so but bear in mind it rarely gets cold enough in the uk to need arctic kit. You'd be best off just adding layers to your existing kit.
Wise purchases would include good base layers (synthetic or wool) inckuding long johns, a couple of light fleece (or wool)layers and a belay jacket, i.e. a warm over layer to chuck on over your shell.
For on the hill, I use a primaloft 100 Rab or a decent down jacket (though it's usually too damp in the uk for down). For bushy stuff I use an old buffalo mountain jacket. The army surplus "softie" gear is a good budget buy.
I've wild camped at -20 in Scotland using the above and been fine.
Excellent recommendations by Stuart, I fully agree with his choices.
The only thing I would like to add is that the first layer ( closest to the torso) can be a short sleeved cotton t-shirt, or even better one of those sleeve less "netting r-shirts" ( do not know english name) and a pair of thin Cotton socks.
The reason is that it is a goid idea to change these two items daily, socks maybe twice daily, as sweat and the skin oils lessen the insulation properties a lot.
They should be thin and light so not to weigh much. We used to leave the dirty items behind.
In bad cold a silk balaclava is nice too.
My experience is gained and learned during 3 years of working as an officer in Regiment K4 in the Swedish Arctic.
Winter temperatures going down to -50 Celcius, thermometer degrees, no windchill calculated.
I've lived in the boreal forst of British Columbia ( 53 - 54N) for the past 40 years. Some winter bush work, sometimes very cold.
From the thread title, only 3 things come to mind:
1. Get out of the wind. Some sort of outer windproof layer. For me, that's a hooded snow camo smock over my coat.
2. Frozen branches are brittle. Stay out of the closed forest on windy days.
3. If a big pine or spruce decided to dump several cubic feet of snow on you, above all,
keep that out of your neck, your mitts and your boots. For me, that's snowmobile gloves and boots.
Or, something like a 36" dump overnight.