Higgy,
The only place we did have icicles on our house (before the complete exterior remodel ) were on the aluminum overhangs, no place else.
We used to get some snow melt at our eves, but the external remodel took care of that. This remodel , as far as the eves are concerned, included spray foam at external wall headers holding ventilation channels (0.5'' inch by 24'') in place in the eves, to about 5" thick. Being an efficiency nerd and having a very shallow 3:1 pitch roof, having ONLY 5 inch of cellulose (total R value of 3.5*5"=17.5) was not nearly enough. So, I made polly-iso foam blocks, 5"thick (R = 6.5*5'' = 32.5), 24" deep block to fit in between the studs, and packed the rest with cellulose. I calculated that the addition of the foam blocks reduces heat loss to the attic by 20%, which is why I went overboard.
More about this is back on the EcoModder site,
Attic insulation - Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com