With low hours and no previous IR experience I completed the FAA IR (including tests) in 2 weeks, in California (good weather!). Yes it was hard work but it can be done. I then came back to convert it, was told I had to do 15 hours in UK plus the test. Trying to find a school to do that was much harder and took a long time to get it all done, despite my good availability. Did much of it during lunch breaks!! If you can find a school that is willing to make an IR instructor available to you full time you may have a chance, but I would say its the UK bit that could be the issue.