Tropical coming inside

I agonize over this every year.

The guideline I use is that the tropicals (baobab, willow leaf ficus, jaboticaba, and lime) should come inside when temps drop below 50F/10C. The weather app predicts dropping below that for one hour tonight, a couple of hours tomorrow, and a few more Wednesday, etc., but not longer than a few hours. Daytime highs are 78F/26F with lots of sunshine.

I think the guideline should include "... below xF/C for more than y hours..." but what would y be? Indoors will be just a grow light and I think they could use the sunshine real well.

How nuanced should the guideline be?

I believe guidelines should be just that. Not fixed rules. They needs to be interpreted with local conditions in mind. Over here when nights fall below 10c in the night the absolute hottest day would be 18c, but most days would be around 15c. In adition to that this is the rainy season. That cold and wet would kill baobabs and proboably others as well.

But I do not do tropicals, I guess you understand why. My citrus and olives is in the greenhouse since end of september.

The guidelines is proboably done with dutch conditions in mind. If you have warm days and fairly dry conditions I am sure that a few hours down to 5c is not a problem. That would be your local adaptations to the guidelines. But beware of heavy rain and take them indoors before.