Check out Bimmerspecialist.ca for the oil separator, least expensive I have found, I priced out the hoses separately and the valve and it was a lot more than this whole kit. This comes up as $155.99. Key is the cold country version.

More importantly check for leaky injector seals or puddles of gas under the truck (yellow brown snow) when first starting up. Winnipeg winters are harsh and when it's -25 C or colder I've noticed fuel weeping from the first injector, had them all replaced two winters ago, still happens briefly at startup. They seal shortly after the block starts to warm-up.

Oil Separator Assembly With Hoses, Cold Country Version.Kit includes-
insulated valve and two hoses. 11 61 7 534 237 GENUINE BMW