It's complicated.
Assume that Nate has essentially no time to prepare for a 5 round fight. You can't go into heavy sparring right now, and even if you could, there is a week and change before media obligations and fight week begins.
Only a handful of people know if Nate got back into serious training after beating Johnson. His last fight was the middle of December so lets assume he took a few weeks off and then you have the holidays.
If he spent January and the first half of February staying sharp despite not having a booking, he might be a decent bet with Conor as a heavy favorite.
Right now I don't see much value in +260.
If Nate ends up somewhere in the +400 > I'm going to put some money down.