I had something like this, round, about 30 years ago. I had it for 20 years, until it turned brittle and broke when I bent it. Never used it but it was good to have.
Absolutly. I drove 10 or 15 miles once with, I guess, no fan belt.
I drove a mile or two or four or whatever until the temp guage started to climb too high. Then stopped and waited 10 or 15 minutes until the gauge went down. Do that as many times as you need to.
Even on a summer day one can do this. It just takes a lot longer.
OTOH, shouldn't run without oil pressure, or with the oil light on, more than the time it takes to pull over.