I would quit. Plain and simple.
Any company who doesn't recognize that my hundreds of hours on the road take a toll on my body and family life, and doesn't think I should be able to keep my hard-earned miles isn't worth my time.
I believe that most top talent would view it this same way. Now if they want to increase my pay significantly to compensate, I would consider. However, I would suddenly start booking on every airline out there so as not to accrue significant miles with a single carrier.