Funny, I see the need to add comments as an indicator that it's time to introduce chunking of some sort--arguably it already has been.
In this case, I'd lean towards intermediate variables, but sometimes I'll use functions or methods to group things.
I prefer function/method/variable names over comments because the are actual first class parts of the code. In my experience, people are a bit more likely to update them when they stop being true. YMMV.
Would it be able to take multiple inputs?