I find a risk in continuing the finnish (it´s through a translation program), so I´ll just stick to english. Ok? :)

My palm trees have trunks that are 120 and 100 cm, so they are a little older than yours. That also makes them a little more hardy, I believe. I don´t have any heating for them. All I have done this winter is putting ...hm... don´t know the english word for it...frigolit..?... on the ground around the trunks.
That way the ground never freezes.
We had one night when the temp reached -13 for a short while, and that night I put green winter cloths (?) over the palm trees. I put a powerful building lamp underneath the biggest palm tree, and only by lightening it up, it helped the temp go up from -13 to about -5, and that´s no killing temp for Trachycarpus. -13 isn´t either, but the leaves on my trees probably got a little hurt. Doesn´t matter that much, though. The biggest tree produces about 10 new leaves every summer.

That´s all I have done to protect them this winter. I hope it will be enough.
I think I will remove the frigolit now since there are no cold spells in sight. It´s much more nice to see the palm trees standing there without any white stuff on the ground. :)
Maybe we´ll get some snow this weekend, so there will be white stuff anyway....

I wish you good luck with your palm trees.
Please keep us informed!

/Pelle