You are not permitted to use flash. Its makes the photos unusable.

Even in small towns you can almost always find somewhere with at least a bit of light. In the small downtown area there are typically lights. There may be a small park or memorial of some kind with lighting. If you are with someone else then they could potentially use a flashlight or something similar. If you truly are incapable of finding any lighting then you should instead sticker that location in the daytime.