Johnny5, I covered all bases, or at least attempted to when I joined NATS.
I didnt burn any bridges with my previous employer, my wife and I decided it would be better for me to go down to Bournemouth on my own until I had finished the course (fortunately I did aerodrome, so it was only 7mths). This can be very hard on both you and your partner, but we managed by me travelling home each weekend and my wife visited down in bournemouth.
This way if all went wrong I still had a base back home where I could find another job.
You need to, and obviously are, giving serious thought to this.
I hope it all works out for you.