The group creater has the ability to remove players from the group, so you could keep the same group, just purge the previous month's leftovers. You could change the password each month too I suppose if there was someone trying to be sneaky and rejoin without anteing up.
I think Yis may have created a new group, he's no longer in the current sbr groups. (You can only be in 3 espn groups and he is in 2 other personal groups)
The new payouts for ESPN SftC is 50k for longest streak, 50k bonus if the longest streak reaches a certain threshold. The bonus carries over each month if the threshold isn't met.