As someone who plays viola and cello, I can comfortably say that a skilled violist could play the cello part an octave higher. As most violists are not used to reading bass clef, it would be a little more challenging in that regard, but it should be doable. However, I am unfamiliar with this piece, so cannot say how food it would or would not sound. Unless Ravel did something very odd, I would expect it to sound very nice.