New Hampshire won't go for Biden, Iowa and Nevada being caucuses is also disadvantage for Biden. His only path is getting endorsements from Nevada's powerful unions in the lead up for the Nevada caucus. If he ends up losing all three early contests, he won't be able to rack up the numbers in SC and by the time Super Tuesday with Texas & Cali come he will be strapped for cash. Those two states coming so early is a disadvantage to anyone who is unable to compete in fundraising and so far all signs point to Biden being 3rd or 4th or worse, in fundraising in the next two quarters. Sanders and Warren have such a huge network of donors that are giving them a small amount every month and a lot of these people are politically engaged, volunteer and will be enthusiastically supporting their candidates during the caucuses. Pete will have a hard time convincing anyone besides old white men to vote for him. So despite being the choice for big donors, he will fizzle out after SC. So a 4 person race until the actual voting happens, 2 person race after Super Tuesday if not earlier - Biden's only hope is that somehow Nevada unions back him instead of Warren/Sanders and he somehow wins the caucus there. This will allow him to do better in SC. But if he loses all three he is done even if he ends up winning SC, it won't be by a big enough margin.
