Unless Paul somehow manages to surge in Iowa before the debate, I think he's toast.
Also very excited for a non-Kasich, non-Fiorina, non-Paul debate.
Don't forget that Iowa has a good ground game for the Paulites, just something to ponder on... Plus, you do know we still have time for another shuffling around in the polls. If the IA caucus were held on this same date 4 years ago, Santorum wouldn't have won IA, for example. So I think we might see a surprise or 2 yet! 
Santorum was polling better at this point than Paul is now. I am as perplexed as you are as to how 10% of the Republican electorate can up and disappear (a good share might have like me jettisoned him for Cruz or Trump), but I do not see it coming back unless Rand Paul lives in Iowa for the next month (and even then, his time would be better spent in New Hampshire).
I actually disagree with this assumption. New Hampshire, ideally, sounds like a good fit for a Paul-like character, but it's already being trampled by Trump, Christie, Bush, Kasich, most people are jockeying here hoping New Hampshire will save them. Iowa is only being fought for by Ted Cruz and maybe some of the religious conservatives, but they are gaining no traction. At this point, Rand Paul would have less of a fight if he just staked it all in Iowa.
I thought about this for a minute before my post. It certainly complicates matters, but I don't think Paul has as much appeal with Christie/Bush/Kasich voters as he does with Cruz voters.
Paul has many cross-over appeals with his large umbrella of conservatism.
Young anti-Clinton not-far-left-enough-for-Bernie voters, internet millennials/gen-x'ers, strict fiscal conservatives, non-interventionists, libertarians, .etc. These demographics swing between Iowa and New Hampshire, it's just sadly not strong enough of a coalition to give him enough oxygen in either state to get traction, and him half-assing his campaign has exhausted his "base".
If he were to somehow be the front-runner, he would garner a lot of support from some of Jebs supporters, Cruz's supporters, maybe some Kasich (
slightly more moderate on foreign policy) fans, .etc.
