I have been cutting designs that are about 16 inches high and 19 inches across. The method is rather simple and could be done even on a Basic. When you put the design in much is left as gray and will not cut or engrave, however if they are spaced a few mm apart they can be cut separately, without worrying too much about perfect accuracy.,
Therefore you put a piece of material as big as your plan in the Glowforge knowing that you cannot cut the upper part. You also plan for places where you can break off 6 inches or so as the cuts reach as close to the edge as possible.
You then make sure that the bottom parts light up and are as close to the bottom as possible, there will be large parts still grayed out and will not cut as yet, but there will be leftover material sitting in the correct place for when it is cut. I also put in a spacer that I know will be just beyond the cutting area so there will be less uncut material. you can also do this on one side (best on the right as it will still show on the GFUI camera even though you cannot cut there so you can see where that line is on your material.)
Then as you have as much lit up red as possible you go ahead and cut that part, As you have created places where the part that is cut can be broken out, you can now do that and now all the rest of your material is visible in the GFUI. Even while you are in Panning mode, you can use Ctl-A to select all the design, and still on panning mode, you can use the down arrow to slide the design down to match