If I were in your shoes, I would let him wait a week, even if he seems a bit hungry. The primary reason is that I would want to switch him over to pre-killed or frozen/thawed mice...and a hungry snake is more likely to make the switch. If they had tried to feed him nothing but crickets, he's probably VERY hungry...and in that case, it's also best to start with a small meal anyhow so as not to overwhelm his digestive system.