How about some low cost foam tops
Before deciding how to proceed, I would ask rather or not your plan to overwinter said nucs. If you are not going to overwinter them, then I would just go with the simple migratory tops. They are sufficient in the summer.
If you are going to overwinter the nucs, then there are more variables to worry about and you definitely need a more reliable way keep those cold November rains out. Some protection from our normal spell of sub zero temps might be a consideration too.