WWFD? (What Would FABO DO??)

Around here, they place heat tape/wire about 3FT from the edge of the roof eaves in a zig zag pattern (45 degrees up and down). That way, they get about 3 FT of the edge snow and ice free. So, a zig zag pattern maybe best. This is done here to prevent snow and ice from dropping off of the roof edges and onto people on the sidewalk below.
Yes. and from my limited understanding that last 3' or so is not insulated from underneath causing the 'drift' over the eave. So basically this is a huge eave , ya? I may not have enough length to zig zag but I could get another bundle. It only sees snow once a year for like two weeks, but its heavy stuff because of the rain that inevitably comes after.

Good idea, thank you!