"Why not fly your N reg on an FAA licence and have a workable instrument rating available to you?"
Quite so. the FAA/IR is far more accessible than the European equivalent. This may change at some point but for now this is fact. Most PPL/IR operators in Europe have taken the FAA route and fly airways in N-reg aircraft because of the inaccessibility of the european equivalent.
Don't let worries about cost or paperwork put you off. Even with the small additional extras it is still easier and less bureaucratic to operate N-reg in Europe.
Annual trust fee for an N-reg £300 or so.
Ferry fees including overheads for my Mooney in 2005 $11,000 (we did not require long range ferry tank installation, the Monroy LR tanks are more than ample for Transport Canada's requirements).
Go for it and enjoy yourself!
SB