We're on our second huge bunch of bananas in a month all ripening at the same time. When I say "bunch" BTW, I don't mean a "hand" of 6-8 bananas, like you might purchase at the grocery store. I mean a whole banana plant's bounty, many hands on a stem, in the neighborhood of probably 30 pounds or so of fruit, 60-80 bananas at a time.
There's only one thing to do: freeze 'em. I've been peeling and cutting up bananas onto parchment-paper lined cookie sheets for 3 days now.
Once the banana chunks are frozen I peel them off the paper and put them in large ziplock bags, back in the freezer. Freezing them on a sheet first, like this, may seem an unnecessary step, but it's not. If you just cut up your bananas and put a whole lot of them in a ziplock bag in the freezer, they'll freeze up in a one big lump. Good luck prying off a handful to put in the blender. Pre-freezing is easier in the long run. The chunks do still cohere a little bit, but not so much you can't retrieve however many you might want.
These will keep us in smoothies for a good long time. Fortunately, we consume a lot of smoothies around here. I add some frozen berries, a scoop of protein powder, and some plain yogurt (and water) to the bananas in mine. If I'm feeling a need to be ultra-healthy I add some ground flax seeds, too, but just as often I forget.