The freeze on the fatty will degrade the meat quality a little bit by making it a little bit mushier as the ice crystals will do their work on the meat. However I dont think the quality would suffer greatly from freezing where you would notice it.
I would definitely suggest that you find a couple of hours to smoke them on your kettle. Fatties dont take long (~2hrs) to smoke and I personally would find the time closer to when you need them to cook them.
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