I don't.
Yes, poll averaging turns out to be pretty effective. They tend to average each other out.
You can weigh the polls, which 538 did.
Of course it's really state-by-state at the start, so what matters in Iowa, New Hampshire, South Carolina and maybe Florida. If you are not in the top 3 one of those you have to drop out.
I'm pretty much trusting the polls that all the people under 5% will not be finishing in the top 3 in any of them, so it's only a matter of time till they drop out - or they may not get in.
Carley is a special case, she can stay in and get the VP slot, that's what she is aiming at, IMHO. Maybe Kasich too.