a yorkie would do ok on a walk that long, provided its not too hot..... my yorkie was 3 lbs at 12 weeks and he is 9 lbs now (i have seen people with the same weight at the 12 week mark and get 7 lb dogs) its not not an exact science, but if at 12 weeks a pup weighs 1.5 lbs, it will be small
another option you might consider is a silky terrier they look similar to yorkies but are larger........
LMAO...... if you want to know about a larger yorkie contact browniesmom