Adam, whatever you do, good luck to you mate.
If it were me and I had too much work, I would:
1. Put up the prices on EVERY job you think needs it. You're going to lose a few, but you have loads anyway, so who cares.
2. Cherry pick the best jobs from your round and keep them.
3. Get rid of the rest and sell them to your worker, three times the amount. It sounds like he is going to screw you over anyway, so you may as well get some money out of him. After that he is just another competitor (so nothing to worry about).
4. Think that if you sub work out, then you will still be worrying about it every day (you may as well employ someone!)
5. Enjoy your holiday.
6. Come back and start back on your own (window cleaning is fundamentally stress free) that's why we do it!
Just my opinion.