If travelling within Europe, I don't really see insurance as absolutely essential. There's EC261 to cover living expenses if a return flight is cancelled, and EHIC if the worst happens. Of course, this needs a big credit card limit to pay for things in the interim, and perhaps a willingness to fight the airline for the EC261 if needed.

Personally, I'd try really hard to find an insurer, but if I really wanted or needed to travel it wouldn't be what was stopping me.