Curious if it is easy (or even possible) to add players into a campaign or subtract missing players (though I think the easy fix if not is to just play them separately). Thanks.

The short answer is that’s its not possible/easy.

you can’t add more players after the fact.

you can have people drop out, but the character they were playing will still be there and you have to run it for them.

In one of the live streams the designers said they tried doing this, but it did NOT work well.

Thank you for the responses, and that's too bad. I ask because my daughter and I are going to start a campaign, but I figure other players might join in for various sessions. Maybe that means I'll have to run two separate or maybe we could each run two characters.