Regarding the clamp light fixture, you should be able to anchor the lamp to something with a shoe lace or some rope to serve as a backup incase the clamp fails as a way to use the clamp fixture safely.
This is what I ended up making for my RT Yellow, it is 15'x10' made from PVC pipe, chicken wire, and zip ties. I also ended up running some burlap around the base so that she can't see outside the enclosure. In the top left corner is her overnight/bad weather box made form a pair of weathertight...
I plan on getting a russian tortoise soon and I wanted to make sure my table and the lighting work well before getting the tort. This was my first real wood working project since building a bird house that fell apart in boy scouts so it looks a bit rough around the edges as I focused more on...
Assuming the night time temperature doesn't drop below the 60's then there shouldn't be a problem with staying outside. Now if you're worried it might get too cold or may not be safe (night time predators or whatever) then there is nothing wrong with bringing it in for the night where you can...
I am looking to get an adult russian tortoise and I know I want to avoid a pet store and I would rather buy my tortoise in person then online. I know there is a reptile expo coming up in a few weeks where I should be able to get a russian but I would rather be able to see where the tortoise grew...