What I would do depends on many factors:
- what my schedule is?
- is there anything I'd be late for by taking a break or short day?
- what are my rain day options?
- how cold it is?
- how much rain is anticipated?
- how many days is it expected to rain for?
- how localized is the rain?
Just an example I was on a dirt road tour up north when it started to rain heavily. I had nowhere to hide, but my tent and no services for a few days so I soldiered on fairly miserably. If I was in a nice town with a hotel and hot tub and the rain was going to only last a day or two I'd be happy to take a break in town and relax until the bad weather passed.
There's no single answer that will work for all cases, but if I can avoid riding in heavy rain I'll do it. If there is no choice - what can you do? I'll just get on the bike and get on with it.
+1
It depends on a lot of things.
But bad weather is one of the reasons that when I plan a tour, I prefer to keep the schedule loose, and to allow for frequent days off.