mnorell

I wouldn't leave the bunches out during anything more than a brief, superficial freeze/frost. If it's forecast to frost then cover the bunch with a towel or other cloth covering so the frost can't settle on the fruit.

If I have late-flowering bananas (after Labor Day), I cut the bunch(es) down the day prior to the first freeze and place them on top of the refrigerator. Usually sometime in January they suddenly turn yellow and are quite tasty. I have done this with 'Orinoco' and the only downside is that, if the fruit are very immature, there may be a "core" running down the center of the banana. This can easily be worked around while eating, and the flesh is still delicious. I'm sure you could also use the ethylene gas/apple-in-a-bag treatment if you're in a hurry.

Congratulations on your 'Ice Cream' bloom, I've waited three years with mine here in my 9a garden, and though my clump has turned into a gigantic thing 15-20 feet tall and 6' wide at the base, with stems persisting from last season, still no flowers/fruit. I personally have found 'Ice Cream' to be a disappointment here for that reason, and also because its trunks tend to rot out in winter here more than other types. 'Orinoco' is a dependable bearer, and one that's far superior to even that is 'Belle.' This monster-strong plant was a mere 6" tall pup in June 2007, grew like a weed and the trunk stayed up and firm through 23F and 15 hours below freezing (plus two other good mid-20s freezes), and a large bunch of bananas emerged from the largest stalk this July, 13 months after planting the pup. It is now a large, impressive clump and I look forward to tasting this Philippine variety.

You don't say what part of the country you're in, but I can say that here in the Gulf states, the warm nights usually ripen bananas pretty quickly compared to chilly-evening areas like coastal California. In the latter climate it can certainly take them longer than 90 days to ripen.