tbf, in January more than 2 a week would be a rush.Gotta love your optimism Gavin:joker:
Point is though, there's bound to be some level of people wanting to get in before the cut, and it's incredibly hard at that time of year to know how many jobs you actually can guarantee to complete. If the weather turns, which it's very likely to, then lots of companies could end up pretty screwed - conversely if it doesn't, then those that too high levels of risk with their installation rates could end up pushing the rest of the industry in to a higher degression rate next time around, while it'd only be them that really benefitted from the higher install rates.
DECC really shouldn't be encouraging this sort of thing at that time of year. If the weather does turn, I wouldn't be surprised to find installers dying while being pushed to meet targets in the snow and ice.