OOOOOOOOOOOOOOOHHHHHHHHH I know I know!! Tear your engine down to a bare block and put it back together with a new block and there you go. No more broken bolt!! j/k
Wont heat cause the metal to expand? If so, wouldnt that actually make it harder to get the bolt out? I would definately try and soak it with liquid wrench. Try a real small pipe wrench. You might be able to get a bite on it.