If Trump wins Iowa and New Hampshire, it's over. He'll sweep every state in the country, regardless of whether he's up against one contender or multiple. Even if Haley wins NH (and she isn't leading in a single poll, while Trump's at 45%), she has to do significant damage in Nevada and South Carolina to stay in for Super Tuesday. I think the GOP race will be decided before I even have a chance to vote. But if it's still in play, you have my word that I will vote for her.

On your second pargraph, first, I have a hard time believing that Nikki Haley thinks Trump would actually be a better option to lead the country than Biden. Christie certainly doesn't believe that. She obviously can't say that, but I would question her sanity if she doesn't think that behind the scenes. I personally suspect a majority of GOP Senators think the same thing and are just too cowardly to say so. It's the logical extension of the original 2016 Never Trump platform. So, given that, go kamikaze and tank Trump's bid for the White House. Worry about the general election after you win the primary. Haley won't be the GOP nominee in 2028 regardless. I don't think DeSantis will be either. None of the GOP also-rans from 2016 are viable future candidates.