I'll be doing the exact same journey tomorrow, just need to decide whether to go the A roads "fun" way or the boring M40 way. With winter tyres on you really have to provoke the car to get it to misbehave at all, very impressive stuff.
watch the weather report, if its going to be clear take the back roads, if its going to be crap take the m40. may have snow tyres, but it doesn t make the zed invincible