Ok help, I still don't understand whether we need, as

Never have reported in.

20 years of having the holiday home.

Why would you need to?  Never have done in multiple visits over 15 years .

Same as everyone here. If at a hotel then they do it but if we're staying at our own place, then I don't bother. 

As a home owner you don't have to - you are already in the system so are traceable, and have a codice fiscale

Ok thanks all.  We're both in the tax system with all the bills to prove it :) so I think we'll keep on doing what we've always done - just turn up and enjoy the holiday.