Depends on the choices available. Last season lots of teams were broken up by single deaths, and new teams formed again later.
For a better understanding of how that works, I would recommend going back and reading through the game posts of Season 4 if you have the time to do so.
Yes. You can only team up with other people that chose an option allowing them to team up.
Do both people die at the same time if they are on a team, or is there a way for 1 person to survive?
Depends on the choices available. Last season lots of teams were broken up by single deaths, and new teams formed again later.
For a better understanding of how that works, I would recommend going back and reading through the game posts of Season 4 if you have the time to do so.
I'll do that, thanks!