I would have thought that your LAME could allow this to occur if you asked them.
I have the same problem, I'm 10 hours from my 600 hourly and if I go on my proposed trip over easter I'll go over. It's a pain in the butt. Luckily I can just write myself a new maintenance release.
I remember talking with some guys who flew from Perth to Melbourne and planned to go back again. They didn't allow for such a headwind and needed to go over the MR in hours, so they rang home and got it approved by the LAME so I just always assumed that it could be done.