He never intended to compete in Iowa, his hope is to win New Hampshire liberal vote and then take Florida and try and ride that momentum into the nomination. As long as he has other people willing to pay his bills I see him staying in at least until New Hampshire is over. If the money has to start coming out of the Bush treasury he will fold up his joyful campaign and go back to Mexico.
The nearest comparison I can think about is Jon Hunstman, who actually did so-so in New Hampshire in 2012 but pulled out shortly afterward because it became clear he wasn't going any further in an actual election than in the polls.