My team has a room that is actually smaller than a field would be, and what we do is we make the field elements that are most important to us. So we set our priorities (Last year it was shooting into the high goal) and then we had a separate little team build the high goal. We made it so that it could easily come apart and be put away somewhere.
So what I would do is prioritize what you want your robot to do, and then build what you need so that it can be easily taken apart.
