Thanks lads, I feel a lot better about the layout now. I've had an idea now, which might be a bad one but I'll tell ye anyway.
Ardree quay is 18 inches wide and 4 foot long, made of 9mm board. If i were to get a 9mm thick, 6 foot by 4 foot board and cut it longitudally into four sections, this would provide four more modules the exact same size. Along with upgrading Ardree's current baseboard, I could quintuple the effective length (all in modules that can be stored while not in use). I of course don't plan on building the layout that far with scenery and all, but I do need an adjacent module to the current one to be able to finish it. I may as well kill four birds with one stone, and so I think i might go through with this idea. If I were to do so, this would be the arrangement. the current Ardree Quay is on the far right. Modules are in [brackets] while scenic breaks are listed in between.
[Fiddle yard(cassette)]-bridge-[Shed/Yard module]-[countryside module]-[Farmyard module]-Bridge under a road accessing Ardree Ferry Terminal-[Current Ardree Quay layout].
I appreciate this might not be too clear but hopefully it gives you a good idea of where I plan to go with the layout basically up until Christmas. Past the bridge on the far left I may eventually add more modules. Ardree Town is intended to be directly beyond said bridge.
I also appreciate that a 20ft long layout may seem unmanageable, but again you have to remember it is intended to be operated either with the fiddle yard directly adjacent to Ardree quay at home, or in its longer state at exhibitions. That is, if I go to any with it. Speaking of, I'd appreciate if someone told me how to get a layout to exhibition. Do I get invited? Do I contact the organisers and ask to exhibit? It's all a mystery to me and I'd appreciate some help.