I did it on my first playthrough (which I understand was really weird). I started Lonesome Road at level 2, and then spent pretty much all the ammo I got taking out the Deathclaws (and even then it took multiple attempts).

I apparently did the DLC in reverse order (starting with Lonesome Road, then Blue Mountain Blues, and then the Sierra Madre), and never met a Ghoul until after finishing the game and backtracking with an older save.

I just ran. Nothing more to it. Didn’t stop until I was close to The Strip. Made the game a lot funnier to me to get encounters that you’d typically get earlier on very late.

With a high Luck/sneak and a stealth boy, it’s not impossible, after fifty tries, to just sneak through the thin net of death claws and just walk to Vegas

Second play I headed due north of Good Springs all the way to the Great Khans, keeping as far distance from the doom flies as possible, I think one or two chased I didn’t stop to look.