Hi Dave. I really sympathise with you, I did exactly the same a few weeks ago, 20 miles from home on a remote airfield. And I've got no excuse really, I've had the car for more than 5 years!
So although I can't offer you any tips for breaking in, I can hopefully make you feel less of a berk - it's easily done , isn't it?
I'm lucky because I do have 2 keys, but the 2nd set was at home and I had no way of calling for help because my phone was locked in the car......
If you've got breakdown recovery, I'd be tempted to see whether they could transport the car home (still locked) whilst you order a new key. They should be able to raise the rear wheels, and tow it backwards with the front wheels trailing if it's in neutral.
Best of luck mate, it happens to the best of us
