Two saran wraps ought to work well—they can cover each other’s limitations.
You can freeze it before you wrap in foil—just give it an hour or so. This way, you can make the foil wrapping a bit snugger without harming the cake.
When I do foil, I:
1. Take a long sheet—long enough to go around the cake plus about 8 -10 inches or so
2. Put the cake in the middle of it
3. Lift the short ends up so they meet and fold it down about 1/2”, over and over until it’s “at the cake”
4. Then I take each side and fold the corners in and then fold, like I did the top, about 1/2” over and over, until it’s “at the cake”
I’m sure there are other methods that work just as well, though !!!!
—ak