I recently bought a BBQ cover from Bunnings. The material appears waterproof, but maybe not the seams. Was under $50 - maybe $30 or so? It's black - white or silver would be better ( I would worry about heat in summer). Still, does a good job. Wouldn't be an issue in your case inside tent. My Telegizmos is quite old and the silver lining is starting to come off, leaving bits all over the gear, so bought the BBQ cover to protect the gear from flaking bits off the Telegizmos cover, which is providing the weather protection.
https://www.bunnings.com.au/our-rang...B&gclsrc=aw.ds