I own a pair of Civetta GTX Extreme
, and love them! Excellent boots!
Now they of course have the Gore-Tex & Duratherm liner, so I have no experience with Lowa's woolen liners, but here
Liner is insulated with quick drying loden wool for warmth.
Unfortunately, wool does not isolate well when wet (info here
), so I suggest you use VBL socks (vapor barrier liner).
I doubt whether you'll find them in size 50 though.
In Europe, the only VBL socks that are widely available are those by Exped
, and unfortunately they stop at size 48. So you'll have to fabricate your own Here
is a ton of info on how to do that!
But of course, that will never be as comfortable as the GTX & Duratherm liner.
So you may want to search a bit longer for the Civetta GTX Extreme
I find them warm, durable, and comfortable.