I understand that non-EU family members of EU citizens also enjoy freedom of movement when travelling with the EU citizen.
I also understand that Switzerland is part of Schengen, and thus there shouldn't be border controls.
On the other hand, while checking the actual rules for Switzerland, I noticed:
If required, they must also have a valid visa C (Schengen visa), unless they hold a residence permit issued by a Schengen country, or were issued a valid category D visa for a long-term stay by a Schengen country
If the third-country national is required to have a visa in order to enter Switzerland and has no residence permit, see Overview of ID and visa provisions according to nationality.
Under 2.6.3 it says:
Passport for a foreign national issued by another state
In order to enter Switzerland, holders of such passports require a visa regardless of the nationality stated in the travel document.
The problem is that, by the time that we were thinking of visiting Switzerland, their entry visa would've expired. It's a C visa, and thus I expect it wouldn't be considered valid anymore.
I was thinking that by travelling together, and having our marriage certificate (or copy of it) with us, it would've been possible to travel and visit Switzerland, even if they haven't yet obtained their Italian residence card. Unfortunately, I cannot find anything that confirms that my impression was correct.
Can the trip go ahead, or is it better to postpone such plans?