DH, our two cats and I are moving from London back to our hometown in a month. While we look/save for somewhere to buy, we are going to stay with DM, who also has two cats. Her cats love me/DH and our cats love her. So far so good.
Neither of her cats are massively territorial, but one of mine is. She is also the only girl cat. They did meet, once, years ago, when we lived 'round the corner and one of DM's cats followed her to my house when she came over to feed mine. But that was through a closed glass door and I'm sure they don't remember 
They are all about the same age, neutered, jabbed etc. DM's cats are quite laid-back but mine are neurotic 
My plan is that I will move two days before DH. DM will drive down, we'll have lunch, then she and I will drive the cats and all their belongings back to her house. DH will stay at the old place for two more days while FIL and BIL help him fill holes in the walls, etc, and will be there for the movers. Then FIL will drive him up to us once the movers have left. DM and I will greet the movers at her house, although most of our stuff is going into storage.
I've planned to follow these guidelines as much as possible: www.cats.org.uk/glasgow/news/introducing-a-new-cat-to-a-resident-cat The room we will use is DM's conservatory. I'm planning to bring their beds and blankets to make dens for them, and I thought I might also get one of these www.ebay.co.uk/itm/like/151401554996?limghlpsr=true&hlpv=2&ops=true&viphx=1&hlpht=true&lpid=108&chn=ps&device=c&adtype=pla&crdt=0&ff3=1&ff11=ICEP3.0.0-L&ff12=67&ff13=80&ff14=108&ff19=0 for when they first meet face to face, so they can't start fighting, and a couple of Feliway dispensers, one for each side of the divide? DH and I are also installing a microchip catflap in the door to our room, so only our cats can get in there. This shouldn't bother DM's cats too much as they aren't allowed in there anyway, although I'm sure there will be some disgruntlement.
How long do you think I should allow for each stage of the introductions? The site isn't really clear. Is there anything else I should do, or something totally different? I really want to make this as calm and stress-free for all of the cats as possible.
I also wonder about food - DM's cats have wet food (they are toothless wonders) but mine have to have crunchy food for their plaque. Is there any way to feed them separately and stop them snaffling each other's food?
I feel really guilty about this. They've had to move a lot since we came to London, and one of the reasons I want to go home is so we can have some stability at last! But I can't make them understand that. I wish there was a way to explain :(