Welcome to our forum.
For the snow and ice - how about using a tarp with bungee cords.For earthquakes - 4 - 10" carriage bolts through the bottom of the spa should keep it from moving off a deck!
I live in West Centra Wisconsin.
The HS dealer south of me had his store come down. Most of the spas were fine. He never reopened that one.
Any time a business doesn't reopen after a disaster I suspect foul play. Perhaps he arranged that earthquake.