OP, I have an 8 year old only-child son. But I'm the one who has the tantrums when he and DH want to shop at Disney, LOL. Man oh man I cannot stand DownTown Disney, either at WDW or DLR. Just WAY too overwhelming.
I find that difficulties with our family are generally caused by lack of REAL food, lack of water, and lack of sleep. When we make sure those things are taken care of, we have MUCH better trips.
A new suggestion I have is to bring money for arcades. My son has an AMAZINGLY good time playing those games. I initially resisted because it seemed like a waste of money. But some of those arcades and some of the games give out tickets that you can amass and then turn in for cheap little prizes. Those cheap little prizes meant a LOT to my son! Also, it was sheer fun for him and DH. Money for experiences is, actually, worth something, and the arcade time that hubby and son have spent has been very valuable.
And since we're both in the position of husband and son not getting a lot of time together, if they can play games together, it's a two for one happy situation.
So I highly recommend putting some money aside for arcades. They especially enjoyed the arcade at All Star Sports.
But really, other than that, REAL food, good sleep, and lots of water.
my DH works 7 days a week, usually about 12 hours a day and I am a SAHM so probably about 90% of the time at home is just DS and I. When we go on vacation, suddenly that dynamic is different with DH in the picture.
Major hugs to you. DH has normal work hours when in the office, but he travels about half the year. So we have a similar situation nowadays on vacation. I don't necessarily referee, but I do try to remind them that they don't spend a ton of time together, and should probably not get so irritated SO quickly.
I bring Rescue Remedy along, too. It's a semi-homeopathic "flower remedy" that sounds like it wouldn't do anything, but it's the "bicker stopper" in my house. We were introduced to it by a clerk at PetSmart, who suggested that we put it in our nervous cat's water for the 4th of July. Worked beautifully, and we found it helped DS, when he was too little for the placebo effect to be a possibility. It's a wonderful thing.
Most of the SAHMs I know that stay home after their kids start school stay home precisely BECAUSE their spouse works long hours, not forcing their spouse to work long hours to so they can stay home!
There so many posts on the DIS where the woman says the man works two jobs so she can stay home, do they are doing just what is bolded above.
I'll admit that I've been off the Community Board for about 6 months now, but I don't recall EVER reading such a thing.
But even if that dynamic exists, it's the couple's agreed upon dynamic, and no one else who isn't the couple gets to have a bit of say in it.
My MIL, who was a SAHM who woke up late, had her oldest feed the littles, sent them off to school, could not help them with homework (and when her husband was in town he REFUSED to help them, saying that no one else's parents helped them which was absolutely not true), and basically had very little to do with the kids except for around dinnertime, AND had a cleaning lady (and still does, while asking her adult children for money for things like medications), had the gall to judge the fact that DH and I *wanted* someone to be at home with/for DS. We also homeschool (and had planned on doing so from nearly the moment we got serious about each other, which was about an hour into our relationship), so it's best if someone is here for that, LOL. Since I'm the one with the education to easily qualify as a homeschool parent here in WA (DH would have had to take a class), and since I was the one nursing the baby nearly 24/7 (voracious little dude), that parent was, and is, me. She judged me for YEARS, even starting a nuclear-style war one day with DH, that I was "making" DH work, when it was a decision WE came to, very VERY early on in our relationship, and truly does work for us.