People have done it in the past.
It is a VERY VERY VERY hard road though
I have seen Tornado/harrier pilots do it in 3 weeks full time
My advice is to do it full time (2 months)
It requires TOTAL committment the IR
Its a tw@t
I am about to return for another crack
at it - I am in the same boat as you
Reducing your block time available will increase the cost and the elapsed time
for the whole exercise
Sorry to be so pessimistic but its all
true..
JAA regulations have increased time and
money for fATPL issue and most will have
quit work for extended periods to be successful