This question is kind of answered, but that solution doesn't work for Windows 7.
I've set margins to 0, no scaling and put colored shape all over printable area (few columns and rows from A1), for testing purposes (image below).
Also, columns and last row are resized to to fit just before creating second page. Used bunch of PDF printers and I got the same result. Left margin has around 1 mm of white margin. Same result with every PDF printer that I used, so it must be Excel.
Is there a simpler solution? Excel can be used to automatically generate documents, I don't believe it has limitation regarding publications or magazines.