I'd say that would be an OK size increase. That is probably the upper limit that you would want to go, however.

From a recent post I left on the houseplant forum:

..... over-potting depends as much on the soil used as it does on container size. You can grow small plants quite handily in large containers if the soil is fast. The only key factor in using large containers for smaller plant material is that you keep the roots free of any extended anaerobic (airless) conditions.

Al