I think snow qualities as very cold and wet, and the gloves are used by the Austrian ski team.
Anyway, the two pairs that I purchased did not come with any leather instructions. I would appreciate if you would scan and post that instruction for treating the leather.
I ordered from the Canadian distributor, coolphotographygear (as an aside: really responsive and friendly, and patient with questions, as you can see below; highly recommend going through them), and in the shipping email was told:
The Heat Company who manufacturers the glove recommends using a
leather oil to moisturize the leather from time to time which will
effectively waterproof the leather such that it will not absorb water.
This treatment is best applied in the evening so that it has a chance
to saturate and bond into the leather overnight.
The outer fabric portion of the mitten does not require any treatment
as it is will not absorb water.
I asked for more information regarding the type of treatment and whether or not it had already been pre-treated and was told:
The gloves are not pre-treated and this only becomes an issue in
milder temps and wet/slushy snow. But just to be on the safe side it
is best to use a mink oil, or a treatment for sweade type hiking
boots. Don't use silicone or acrylics.
After discussing some choices of conditioning/weathering agents (and being told to avoid wax-based products to avoid residue from transferring to the camera/lenses), I was recommended this:
I note that it has silicon, which I was told to avoid, so have just written back to Michael of coolphotographygear for clarification, wondering if I should use pure mink oil instead (if I am forced to go through the "squashed mink" route).
UPDATE: Within minutes of sending my email described above (on a weekend day, no less!) I heard back from Michael of coolphotographygear:
I would use the pure Mink Oil in liquid form not the paste. Once you apply it use a hair dryer to open the pours and to allow it to really sink in. My business partner did this method and then ran it under water and it worked well.