How big are salvageable rhizomes?

New to DG AND irises here. :) I've been "rescuing" iris rhizomes that our house's previous owner had either not been splitting or planted in an area that gets too much shade & had been overgrown by some sort of all-encompassing-plant-eating-parasitic-vine... the ones under the shade & vine have rhizomes that are only about 1" long, and I've never seen them bloom... should I plant them in something & let them mature this year? Are pots okay, and what potting material would you use? There were probably 12-18 of these small ones.

See if the articles on DG by Jill M. Nicolaus (critterologist) can help you figure out what to do.