Welcome to the forum Kevin!
The type of insurance qualifications require you to have a 2nd vehicle.
If you don't, then you cannot. I'm sure there are many people able
to beat the system. So having a requirement of a physical 2nd vehicle
makes total sense.
What you can do is purchase insurance that limits you to a certain
mileage per year. If you drive your car under 6,000 miles a year
then you can save a good amount.
Hope you find a garage that isn't at least double the price of
Disclaimer: Remember, I know absolutely nothing, but it doesn't prevent me from having an opinion or suggestion.