The main purpose of repotting is to provide fresh media. The pot does not need to be a lot larger but should rather be selected according to the size of the root mass. Orchids transferred to overly large pots tend to be over-watered and plants suffer from root loss.
The type of pot selected may influence watering frequency. For example, clay pots require more frequent watering, as they will dry out faster. Always select pots with drainage holes. It is recommended to place pieces of broken terra cotta or Lambert Horticultural Wood Charcol in the bottom of the pot to encourage good aeration.