So..... How's your day going????

Yep, that looks like a meteor impact crater.

Try to pinch it closed; crimp it, with needle nose pliers first,
to make the spot of pressure as small as possible,
(a screw will just make it bigger,)
then Brake Kleen, then a bath in acetone, to cut the ethylene glycol.
Then take U shaped thin wires and thread them thru from the inside,
and twist the ends together to cover the hole, for some support
and strength - so it doesn't just blow out. 6 or 8 should do it.
Then JB Weld. Bigger is better, and take a putty knife and pack it.
I hate "Voodoo Mechanics," like head gasket fix in a bottle, but
a buddy of mine did this fix on a tractor, and 5 years on it's good.
The wire thru from the inside in a star pattern, twisted tight,
is what makes it withstand the pressure.

 

From the picture I thought it was a hit from the outside.
Hence; "meteor strike" - sorry, bad joke.
Same theory applies regardless.
Without the wire first it will just blow out, (or in.)
Even an incredibly small screw doesn't have enough
surface area to hold 30 lbs. system pressure.
The wire anchors it rigidly to not blow out, as
it wraps around the other side and is twisted tight.

 

Good for you to - keep it on the road - with a "macgyver" repair.
I see you had wire ties with you, (I once got home with a blown
hydraulic hose wrapped with rubber gloves, and wire ties.)

I forgot to mention keeping the cap loose, another good idea.

Potentially thousands of dollars lost,
if you just throw up your hands and quit.
You're not like that.
I'm not built that way, either.

Buy new radiator - $$$
Refill cooling system - $$$
Miss pickup/dropoff appts. - $$$
Plus, your time, or shop labor - $$$
Fixing it on the side of the road with a rock and a stick - Priceless

So... final update on the clutch that keeps on giving.
Thursday the parts were still on a Fed-Ex truck somewhere,
never got them until Friday afternoon.
By then, I had all the incorrect parts out,
and had the new ones in by Saturday noon.
Works like a new one!