I've been looking into this as well lately. Last year I replaced the valve cover gasket and only cleaned the hoses to the oil separator.

There is a "Cold Country Version" for the 3.0l PN 11-61-7-534-237 with insulated hoses and valve.

Local dealer in Winnipeg is doing a lot of them as people have been buying cars from the US that aren't neccesarily fitted with this part. They also want to change the steel dipstick tube?? and the hose from the valve to the dipstick, as a minimum. Checked with a dealer in Minneapolis and they carry the parts and are doing the upgrades as well.