The pilot test
Instead of launching a test for all our users, I would recommend a pilot test. This means trying our test with just one or two users.
The pilot test is usually done during the first day of a lab test. You just invite two participants with maybe a third as a backup plan, just in case one or both do not turn up. Two tests will not take the whole working day, so you could use the rest of the day to improve and correct the test, based on how smoothly the pilots run.
With remote testing, it's even simpler as we will see in the next section. Just launch the test with a user, watch the resulting video, and correct the test design if needed. This can be done in two or three hours tops, and then you can launch the improved test. When you launch the pilot for a remote test, chances are, you will have some users who are online and willing to take the test if your user base is broad enough. Of course, if you are only interested in corporate treasurers with five cats, you may need to wait...