I can’t comment regarding the fishing on Great Pond, but will say after living on Messo for 4 years it is hands down one of the more dangerous lakes to ice fish on. The ice thickness varies and unless you really know the lake or are with someone experienced With the safe areas, you should really rethink hard water fishing on Messalonskee.
That said, we’ve had lots of success catching pike this year, but the majority being caught are small fish. Seems strange because a few years ago, we were pulling monsters from the lake.
Good luck and tight lines...