I have a LOT of outlets in my garage/workshop. I might consider getting a
GFCI breaker rather than rewire all the outlets

You just need to put a receptacle GFCI in the first outlet in each branch
circuit, connect the outgoing wires to the "load" terminal.
If you have "home run" each receptacle that won't be as easy and the breaker
route may be an easier, if more expensive, solution.
From a real world perspective, the most important outlets are the ones that you
will be using line powered hand tools on. "Fixed in place machines" with line
cords safely routed out of the way are significantly safer than a hand tool
that could have a damaged cord, missing ground pin or whatever. There is an
exception to the GFCI rule that would cover the fixed in place equipment if
there are no other accessible outlets on that circuit.
You are also more likely to be sitting on the concrete floor when you are using
that hand held tool. This can provide a very dangerous fault path through your
body and that is why the GFCI rule was implimented.