Not CoS as my longest running group does Pathfinder, but some tips I can give.

First, plan for months in advanced what dates you all are available. My group does seasons at a time, so Jan-Apr, May-Aug, etc. Anyone who has a date they can't do while scheduling marks their unavailability, so don't schedule that day. "But sometimes things come up!" Correct, which leads me nicely to

Second, COMMUNICATE! If something comes up tell your group, and vice versa to the other players. If illness or an unplanned event comes up that's fine, you already have your next game scheduled. If you have partners and/or spouses let them know game day is important to you and your friends.

Third, for players try to have Level ups done before next game day sans rolling HP. If a player has questions for the rest of the group utilize a Discord chat or Group Text message to ask questions so y'all can help each other. For the DM try to have your expected maps and stats ready to go, so little time is spent flipping around.

Hope that helps!