sprawlable
Any object deemed to be worthy of sprawling (essentialy, collapsed upon something) due to lazyness, tiredness or for comic effect.
Matt found his piano Very sprawlable while Fiona was playing
sprawlability
A term to describe the available room that a couch, bed, or any other sleepable surface has.
A king size bed for one person has good sprawlability. A twin sized bed has limited sprawlability.