Hi,
You can go to your camera attributes and change the far clipping plane setting to a much higher setting so that you can go even bigger without your geometry dissappearing. I've got mine set at 100,000 right now.
Next, don't be afraid of going bigger. If you go to Display/Grid Option box, you can change your grid settings to suit your needs. You can also go to Window-Preference/Settings and change the units (feet v/s centimeters, etc.) in the settings section. You can also use inches or centimeters and then pretend that 1 cen = 1 foot etc. if you want it to be to scale.
If you're not doing it to scale, then I personally would definitely go bigger (maybe 2 or 3x bigger). BUT, wait a little bit to see if anyone else posts a better answer for you because I'm still a little new to all this.
Best wishes on your project.
Don't be satisfied with what you can do but rather strive to do the things you can't do!
Exceed Expectations!