Format of the manuscript at the revision stage
Reviewers are concerned with the technical content of your paper, not the formatting.

Even if you're using a LaTeX-based style sheet, it's not necessary to worry about making sure everything fits within the margins. If the paper is accepted, the journal will probably work on your paper to make sure it follows their style guidelines when published. 

So just worry that the content is correct, and submit a single-column paper for the reviewers to read. It'll make their lives easier, which will thus make your life easier. (And you won't waste time fiddling with LaTeX!)