Is it OK to install the Edge Vent on a house in the North (snow and ice dams) when there are gutters on the roof?

Yes, it is acceptable to install The Edge Vent in slow climates.

If ice dams are a concern, The Edge Vent is safe for use in ice-dam environments and it is an effective deterrent to ice dams. Moving the Edge Vent up the roof deck reduces the amount of ventilation at the soffit, where you need it the most to fight ice dams.