Interesting on how your current draw or load readout may tell you what is actually going on. You can't do more investigation or auger a hole on demand since you aren't there.

It does make for an interesting solution... could you rig up a few rounds of plastic explosives or dynamite, put them in a strategic place between shore and the typical place where a dome will show up and detonate using remote commands? You could place 4-5 charges there under water and over the course of a bad winter, detonate when needed to keep the blast zone open and keep any air that wants to build up under the ice above the diffuser moving over to the blast zone and then venting out there?

There has to be someone on this forum who has experience with explosives?