You can change the page dimensions if you need more width, if that's what you mean. Or, more simply, create a second page and move stuff there and juse the page layout to jump back and forth. And finally, drop stuff into and out of a library.
Now I get it. You could effectively double your "pasteboard" area by creating a spread in Quark. If you have an 8.5" x 11" page then a spread of that will give you an 11 x 17 with more pasteboard room to spare.
Yeah that will work. Seems kind of a sad way to do it. $1500.00 for a program where you have to find lame ways of doing things like this... No wonder Indesign is taking over...