Thanks to all of you for your insight on this issue.
I'm the Wolf den leader for 11 active second graders* (up from 8 Tigers last year). I never received much guidance in terms of meeting frequency from other leaders, so last year in Tigers we met three times a month (one pack meeting, one den meeting, one Go-See-It). This may be standard practice, but thinking back 30 years to my time in Cub Scouting, it didn't seem like enough. It must have been fine in our case, though, because all of the Tigers except one, who moved away, are now Wolves.
Now, with more achievements to be complete