How old is he now - if he is not yet 3 months, he is still very young, and the outside world is probably quite intimidating...
I wouldn't drag him at all - just take it at his pace, and make sure it is fun. It doesn't matter if you only get 25 yards, as long as he learns to enjoy it.
Personally I would go armed with treats and lots of praise..... even if you just sit 10 yards from your front door and play for a little bit, then go home... Monty needs to learn that the big outdoors isn't all that bad, but in his own time.
Honey still pulls more on the way home, as she always gets a treat after being dried off, but she adores her walks.