Kristy ... Stewie won't forget you!! Yorkies, I have found, are kinda like elephants ... they never forget! Potty training, maybe ... people, never!
Although we have never left Toto overnight, she has other people in her life that she loves ... i.e. our granddaughter has a room in our home [in Alabama] and sleeps over when we are there. Toto adores her and if she even hears Kayla's name she gets excited!! So don't ever think that Stewie will forget you ... he won't!!