I probably have 2500 to 3500 miles left in my tires. However I am at the end of June riding out to Reno, NV, then CA and up the coast to OR and WA. Knowing how much faster tires go away in the heat and out west, new tires are going on before I leave.
My wife learned the hard way about running a tire to long. She was on the Blue ridge and call and said she had no tread left. I told her to go to the nearest dealer in Asheville right away as they were 40 miles from it. She said no she though she could make it to Smoky Mountain, our normal dealer. Said she was going to take it slower and easier. Well when she had the blow-out the closest dealer was Pigeon Forge. Luckily she did not go down. Scared the crap out of her and the three other ladies she was riding with. She said it sounded like a gun shot.
I'm sure she will never let her tread get that low again.