moving a cat

Question
I would like to move my 15 year-old, male cat into a home with my fiance and me.  Currently, my cat lives at my parent's home, where he has been his whole life.  My parents now have a vacation home where they spend most of their time and my cat is left alone quite often.  
The reason why I am most concerned about moving my cat is that my fiance has two 5 year-old female cats.  Our house is large enough to allow all cats to have their own space.  I am worried about my cat's age and the stress a move could put on him.  Is this move possible?  If so, what is the best way to integrate the cats?  Any advise is greatly appreciated.  

Answer
The move will be stressful for all cats concerned, but just introduce them slowly and cautiously.  Give your male a small room with his food, water, and litter box so he can get used to all the new smells and sounds for several days.  The other cats can interact with him under the door. Then try letting him out a little at a time,(supervised, and see how it goes.  Things will probably be OK after a week or so.  Good Luck.