D.K.
13.5 months is still very young to deal with a lot of upheavals at once. All of the things you mentioned qualify as upheavals for a toddler. They're very sensitive to changes. I would take it one change at a time. First the vacation...he's not going to really understand what's going on, so I think the comfort of that constant in his life will be important for maintaining his emotional equilibrium. Again, same thing with changing child care arrangements. Wait until he's settled in well in the new child care arrangement (maybe a month to two months) and then start weaning. You don't want him feeling like his whole world is being turned upside down, so keep that constant comfort for him until you have the chance to make weaning the only odd thing going on. He'll be happier and I'll bet you'll have better success.