I found this which leads me to believe I could run the vent vertical up as high as I can up inside the base cabinet and then run it through the wall at 45+ degrees into the attic space and try to achieve 6 inches above the sink rim which I think is barely possible in this case. That should meet code shouldn't it? That way only the vent is outside in the cold; what's your gut feel on that?
4715.2540 VENT GRADES AND CONNECTIONS.
Subpart 1. Vent grade.
All vent and branch vent pipes shall be so graded and connected as to drain back to a soil or waste pipe by gravity.
Subp. 2. Vertical rise.
Where vent pipes connect to a horizontal soil or waste pipe, the vent shall be taken off above the center line of the pipe. The vent pipe shall rise vertically, or at an angle not more than 45 degrees from the vertical, to a point at least six inches above flood-level rim of the fixture it is venting, before offsetting horizontally or before connecting to the branch vent.
Subp. 3. Height above fixtures.
A connection between a vent pipe and a vent stack or stack-vent shall be made at least six inches above the flood-level rim of the highest fixture served by the vent. Horizontal vent pipes forming branch vents, relief vents, or loop vents shall be at least six inches above the flood-level rim of the highest fixture served.