Printing 20x30 with the OLD Dp2: Possible or No?

This would be a matte finish, no cropping.

Does the image need to be "upsized" or anything along those lines (no idea what this process entails but have seen some mention it)? Would such a process allow or even larger printing than 20x30?

The plan as of now is to drop the digital file at the local print shop and just let them have at it, as is.