@Olibob, You decide what to do. It's going to be
your diorama after all.
What I can leave you with are some questions which may help you determine what you'll want to do.
1) What is it about dioramas do you like
so much that makes you want to make your own? Is it how well it simulates a real-life setting at a smaller scale? Is it because you want to give toy cars a world to live in?
2) Can you afford to make something huge? In what sense? Financially- yes, but more so real estate. I've seen some people use up an entire space where their breakfast/dining table would be. It's totally awesome to have something large because of all the magic you can make happen and take convincing photos of a landscape, but at the same time, do you really want to go that far? I mean, if in the event I lose interest in dioramas, or need to move to another house, what the hell am I going to do with something like this? I can't bear the thought of taking apart something I put so much time into creating, but it would be a hell of an inconvenience to have something so big take up so much space in your place of dwelling.
I'll share with you why I got into dioramas:
I am largely drawn to learning how professional artists do things; music, visual arts, movie effects, studio photography, CGI, animations, sculptors, fabricators, you name it. And with that I do enjoy the process of getting into it myself.
With dioramas, I found myself initially interested in the idea of building your own world when I was little, but I would never have the supplies (both access to, nor the funds) to make it happen. I would craft these "parts of the world" with whatever scrap materials I have on me. Usually it's just paper, cardboard, tape, and a marker. It was fun to make something, but in the end I wouldn't be content with it, because it clearly still looks like scrap material. No matter how straight I draw the sidewalk cracks, it still looks like drawn lines on paper.
Fast forward 15 something years, I get a part-time job so I can afford to buy some better supplies to try something for real. With all the little-boy and big-boy cars I've collected, I'm limited on space. Yet I'd still want to make dioramas look as real as possible with whatever I have. I found a compromise of the two where I can have both, and this is the first one I made some years ago:
I wanted to give the impression I used a large space to capture this photo, but in fact, this piece of land is just two blocks of craft foam I hacked away at with a knife:
And the only way I thought of doing backdrops without taking it to a real location or printing out something huge was to use my computer monitor:
To double up on this, for every custom Hot Wheels I did in nail polish paint, I made a new diorama to go along with it. If you want to see more, you can visit my blog post
here, and look under the "Dream Cruisers" section.