Pretty much what we've done with the 3 boa's we have here. The big adult female, Tequila, will go anywhere from 2 to 3 weeks on a prey item depending on if she's eating xxl rats or smaller rabbits. The rabbits seem to keep her more satisfied for longer but basically we just go, with her, on how she's acting. Tequila will let us know when she's ready to feed again but then she's a mature, adult female of over 16 years of age so she knows her business real well.
As far as husbandry, I'll have a look through our caresheets here and if we are lacking in the boa area then I'll bring it to the staff in general to see what can be done about that. I've kept our boas in glass, in plastic and in a custom climbing cage. I think they do well in all of that as long as their needs are being met. Personally I keep the boas at about the same humidity as the balls and just a few degrees cooler.