The short version is… it’s doable.

Barely.

I’m using this map to do the calculations, by the way: it’s already adjusted DE & NH to Likely Democrat and Tossup, respectively (which looks accurate to me, although the latter at least is volatile and speculative).

Conclusions?   …Well, it’s going to be easy to get to 46.  Deceptively not-impossible to get to 48.  51 is going to be hard.  The good news is that NH may not actually be affected by whatever changes take place, which will make the fifth wave a heck of a lot easier to deal with: three of five is better than four of five.  But note that even then I have to assume a sweep of the fourth wave in order to get to the fifth.  I also have some slightly annoyed things to say about the state of the NY-SEN races, but we’ll let that slide for the moment.