For crappy winter conditions you’d be better off on a singlespeed. Then once you’ve eliminated the need to spend money on gears you start making it british winter proof but spending money on the bits that british winter’s love to kill like the hubs, BB and headset.
Spending £400 on a bike for winter that still has gears isn’t going to save you much in either maintenance or money relative to just plugging through the winter on your normal bike (£400 buys a lot of cheap cassettes and chains). Add to that they’re unlikely to have as well sealed hubs as an expensive bike, and if you’ve not been riding 15+ years you’re unlikely to have the tools to change a cartridge BB.
If it had to be one of those two then the Voodoo has hydraulic disks at least.
I just picked up a Charge Cooker single speed off the classifieds for £150, in fact I rode in on it today towing the trailer in shitty conditions for 25 miles. It’s great because everything is actually standard!
6-bolt hubs
IS calliper mounts
1.1/8 external headset
29″ wheels with normal tyres
QR hubs
Threaded 68mm BB
Which means when stuff breaks (I snapped a crank bolt last week when the crank came loose and I tried to nurse it home) I can just grab something to replace it from my overflowing spares crate! It’s a perfect winter bike!