Just a gut feeling, but I think the first idea is somewhat based on wishful thinking.
If I were to be asked to design such a system, I would attempt to put strings of smaller devices along the relevant surfaces...imbedded in the surface like...erm, rivets.
Relatively low levels of energy would cause the ice to melt at the adhesion point, because there would be no need to heat the metal.
It would be a difficult system to retro-fit.