I just discovered something that might be of help, although I haven't tested it, if someone does please post your results.
In Adobe reader, there is a booklet printing function in the Print menu. In Adobe Reader, go to File, Print, look in the Page Handling box. In Page Scaling, choose "Booklet Printing". That should create pages that are scaled down by half, rotated 90 degrees, on one page. Thus you should have your 8.5" x 5.5" booklet size without having to make any changes to the original.
I just discovered a problem with the above anyhow... if your browser is configured to open the pdf
inside your browser, "Booklet Printing" isn't available. If your browser is configured to, or you decide to open the pdf in an external Adobe Reader window, only then is "Booklet Printing" available. This would be too confusing to rely on, so a resize of the document makes more sense in the long-term.