Get a can of Huberd's Shoe Grease or a can of Snow Seal.
Heat your oven to 200F. Keep the door open and put your gloves on the oven rack. Let them get warm/hot. (Watch them -- you don't want to fry the leather.) Then get your can of waterproofing goop, open it, put the gloves on, dip a finger into the can and start doing a "washing your hands" motion, to work the goop into the leather. Repeat as needed.
Get a good coating of the goop on your gloves, then set them back on the oven rack for awhile and let the heat work the goop into the leather. You can put the gloves back on after awhile, and wipe any excess goop off on a rag. The gloves will be nice and soft and waterproof under some pretty severe conditions, but the leather won't get softened so the gloves will wear out faster. They'll be fine.
I live on a beef cattle ranch in coastal Alaska, in a wet climate. I wear Carhartt brand insulated leather work gloves all winter, and came up with the above process out of frustration. It works.
Re-goop the gloves as needed. (Doing my process about twice all winter should do it. Winter last for 7-8 months at my latitude.)
Jan