Ouch, that hurts.
Chrom: From what I have seen in past, ... When I was in Armenia they had fig trees there and , in Armenia, the winters are very cold and harsh. You would be surprised how much beating a fig tree can take before dying off... In your case- Your trees are not mature enough to hold so much juice in the bark to protect the entire tree from freezing and dying. And also, have in mind, Seattle has gentler winters than Caucasian countries. So, what I am trying to say is that, maybe you should try something like this: Take the thickest trunked tree out and berry the entire pot into the ground and see how it will handle the winter. If it makes it with minimal damage then you can put everything in ground and let them mature :)
And as for your thin trunk fig trees, I think you better get some serious growing lights ASAP, or? snip the tips and make sure you drop the temp of the garage further down. that will stop the growths and put the plants back to dormancy.
This is my opinion.
Good luck and let us know how they come out of the winter bud.