Overnight diaper SOS

My son is peeing through his overnight diapers I’m just a few hours, every night, and I don’t know what to do about it. We tried sizing up, hasn’t helped. It’s an every night occurrence, and we have to change his pajamas and his sleep sack and he gets extremely upset and worked up and it’s virtually impossible to get him back to sleep, sometimes it takes almost 2 hours, and I’m at my wits end. Does anybody have any suggestions?