My fumbly fingers would have trouble holding that, much less cutting it. You did a great job. Apparently, you use a magnifying glass.
I have trouble printing 11X17 from Inkscape also. Usually what I do is make any modifications I want to make in Inkscape (fill and stroke colors) and then save the pattern. I then open a "Draw" program, format the page size dimensions to 11X17, and then insert the picture from file. So far that has worked every time for me. I say "Draw" program because there are several out there. I use Open Office because it's free and does almost everything Microsoft Office will do. Hope this works for you.