Hi bsacco and welcome to Retouch Pro,
The 110% method damages low level detail really quickly, and I usually advise that it not be used. Check out my post
here for examples and more info on why and how.
Drastic resizing involves a lot of bluring and magnification of imperfections. But this image looks like the detail should hold up pretty well to this kind of work.
Standard poster sizes are 22x34, 23x35, 24x36, 27x41 and 30x40. Because it would be really hard to crop to one of the other sizes I would go with a 30x40 or a proportionally smaller one and matte it (for example 24x32 with a 4 inch double matte).
Open the image, without resampling, change it to 100DPI (most poster printers prefer this because anything more over runs the buffers in the printer.) Turn resampleing on and double the image size (bringing it up to 24x32) then increase the image size up to 30x40. This will minimize the interpolation and maintain more of the detail.
I usually suggest one should never resize an image more than once, but increasing by more than 200% or reducing less than 50% is the exception.
Hope that helps,
Michael
Photoshop Contact the people you want to print it and ask them what resolution to use.