I think it's safe to say now that it'll be cold from now until at least later on next week. After that there are too many variables to take into account so until we get to Monday, I wouldn't hazard a guess as to what is going to happen!
Worst case scenario for end of next week (if you like...
Start of the downgrade to the potential cold spell? Not liking the ECM this morning, UKMO looking good as is GFS. However until we have complete support for the block around Greenland, we could just end up with high pressure over us for a few days instead! :US:
The 12z runs for the big three...