I would let everybody on the frequency know, that I have some serious problems. Best done by using the magic word, MAYDAY. In my case the aircraft wants to change about half of the air below to be above, even more if heavy and in icing conditions.
Drift down might be considered, as we fly around the Alps, or even better to Georgia with its caucasian mountains getting up to 5.000 m.
Homebase is always a good idea, if you don`t get yourself into deeper troubles because of a large distance. 100 NM is not that far, but why flying away from a perfectly usable airport? Decisions have to be made, thats all. After that, discuss it, learn from it, agree or disagree with the actions but keep a profesionell level throughout the discussion.
chris