I've got one of the Kovea adapters. Good product -- with some important caveats.

First, be really careful if you buy one. There's a tube inside the canister that, when properly oriented, feeds gas into your stove. If you mis-orient the canister, you could have liquid fuel going into your burner, which is a problem (unless your stove is built to handle it). Not all remote canister stove can handle liquid feed gas.

As to improved cold weather performance, maybe not. OK, let's say you've got the basics in place: a stove that can handle liquid feed and a way to orient the tank and Kovea adapter such that you get liquid feed. All well and fine. Now then, what exactly will push that gas into your burner? Vapor pressure of course. And in cold weather with a canister full of 100% n-butane, you have how much pressure? Not much. So, would that adapter somehow allow you to have improved cold weather performance using the inexpensive "long" butane cans? I don't see it happening.

Well, then why does it work on something like a Coleman Xtreme? Well, recall that the Xtreme's fuel is not 100% butane. In fact it's about 40% propane. That propane creates quite a bit of vapor pressure, pressure sufficient to pressurize the tank and convey fuel to the burner.

Not trying to say anything bad per se about the Kovea adapter, but a) make sure you know what you're doing in terms of the orientation of the canister and b) don't expect improved cold weather performance.

HJ