Is all hope gone for this pup to be housebroke?

Two months ago I took in a small mixed breed puppy that a friend was going to take to the pound because he could not get him potty trained. I figured he wasnt trying hard enough and so we took him in. He is now 6 months old and I am starting to wonder if he is just too old to learn not that he has been peeing and pooping inside his whole life. I want to start crate training over, but wanted to see what everyone else thought. I do take him out on a leash every 2-3 hours. Its too cold to leave him out alone and hes too small to be an outside dog. Please no rude comments. Also, he has an appt next week to get neutered.