Is it possible to drive a car 50 miles with a bad lower control arm

If I was you. Pull the wheels and rotor off on that side making noise and check the wheel begs really good to make sure the brg races aren't spinng in the hub. You wnt feel a couple of thnds play by hand. My old 68 chrgr did this on both sides.

I agree fully. I can't imagine a "grinding" during braking and steering that is "safe enough to drive."

Don't you have a buddy with a trailer?