With blueberries using too large a pot is usually not much of an issue. With other plants it can be, and should not be done. It's Ok with blueberries.
No, they don't like to be wet, like it very moist all the time, root rot though is rare in blueberries. Still best to dry out between watering, not super dry, just dry. But for a week while on vacation the plant should be fine. I myself hire the local teenager who cuts grass to water my plants.

Super! You gave me great advice. Thanks very much! Huge help