The standard resolution for printed magazines is a 150 line screen, IE 300 dpi.
As Nathan points out, high contrast detail works better, but on average the Epson gets somewhere around 2100 to 2300 spi.
Therefore you can enlarge by a factor of around 7x or 8x at most, and still get 300 dpi.
If some of your negatives contain only 30 lp/mm, then you ought to try this before purchasing the scanner: You may not be delighted with the results, even with a perfect scanner. They may not be up to the standards of Large Format photography. Find out for yourself.