Located in the Hudson Valley- NY-We have a very large 75+ year oak tree in our front yard. It appears to be dying at the top showing browned or no leaves in certain portions. In addition, a section of the lower bark is coming loose and has some carpenter ants, smaller ants and eggs living in the dead wet bark. The wood behind is in good shape. I removed some of the dead bark to prevent moisture collection and rot. What can I do to save this tree? I keep getting mixed reviews from arborists telling me to either cut it or keep it.