If you push to get everything done quickly, get booked on a course for the IR and then I can't see why the CAA won't give you a possible extension, especially as they have set a precedent and done this on a number of occasions for various reasons for the helicopter IR over the last couple of years.
In all honesty, it isn't too difficult doing the IR theory exams, more of a pain in the ass than anything, but it's more time and money for no more knowledge! Another CAA money making hoop to jump through.
Good luck.