Cakewalk, the company, has closed.
All products have been bought by BandLab Technologies. This was only a few days ago.
Tech support is currently (almost) none existent but will hopefully start to improve in the very near future as the new company gets up to speed.
To answer your "demo mode" concern, run CCC to force connection to the authorisation server (which is still working). Your Sonar licence should have been upgraded to never expire, even if you didn't complete a full 12 month pay instalment cycle.