I've lurked for ages but am only finally posting so ... here goes.
First off, I sincerely hate for you that your vacation is getting off to such a bad start. Hopefully this is the absolute low point and it is only up from here, right?
Last October I took my seven year old son to the Mouse House for the first time. In fact, his first vacation ever because being a single parent who has only received child support when the law catches up to his runner dad... vacations are tough to afford. We camped at Fort Wilderness. We got a tent from Goodwill which was probably not my best call since it did not work. Stop laughing. It didn't work for me, the many other campers who attempted to assist, nor the wonderful people working at FW. It was one of those push the button to open things. Now I know why it was at Goodwill. Money was tight so it was not like I could just get a room so we... camped in the car! A Toyota Echo. Go look it up to see how "luxurious" those accommodations turned out to be

. I cursed a blue streak for about 20 minutes and cried for another 15 and then something really awesome happened. Some other campers donated some decorations and helped us decorate our car and campsite (for Halloween) and that made me feel better. One guy brought over a juice box for my boy and a bottle of wine for me. I felt better still. Everyone agreed that Goodwill had not, in fact, shown much good will. We all laughed and I felt even better. My son and I hit the parks and looked for all the magical moments we could find... and we found tons. We came back to our campsite and it started to rain at which point my 7 year old declared it was a good thing we had the car so we didn't get wet! There were honestly magical moments every day of our four day trip. Enough that I took a second job so that we can go again this October. This time, with a traditional tent which I've practiced putting up and taking down repeatedly.
My (long-winded) point is this. You're unhappy now? OK. But allow it to pass and actively look for the magic. You will find it. To paraphrase one of my heroes: The greatest madness is to see life as it is, rather than as it can be. (Don Quixote).
I truly hope you have a vacation at the GF which is at least half as wonderful as the one I had with my son last October.