When we wanted to take a "bonus" trip to DL 10 years ago (we were already heading out West for a wedding, but I desperately wanted to add a side trip to DL that was NOT in the budget), I knew I had to find a way to save money that was NOT designated for anything else. I had two small kids and was a SAHM with just a small at-home job that didn't offer much in the way of more hours.
The first thing I did was sign up as a Subsitute Teacher in my kids' school. It took a few weeks to get interviewed, finger printed, and background checked, but I started working immediately after all of that and worked pretty much as much as I wanted.
Then I made a poster/visual for the family that showed all of the "small" ways that we could save money around the house. I had examples like .....
skipping fast-food snacks for a month = $20 saved = 4 Mickey bars
using just ONE paper towel to dry hands x 4 people x 30 days = $2 saved = 8 pressed pennies
That's just an example, but we really buckled down, tightened up everywhere it was reasonable..... we live a fairly frugal lifestyle already, but I tried to look for ways that the whole family could contribute. And every time we "skipped" spending money somewhere I made sure I took the cash and put in an envelope for the trip.
These days I do things like grabbing side hustles whenever possible (recently made $80 helping someone empty their basement after a flood), taking extra work days when available (I work per diem), selling online (FB yard sales and occasionally Ebay), and BUYING very little and buying USED whenever I do need something. I also pack lunch for DS and myself EVERY SINGLE DAY without fail. I NEVER waste food either.... after our mortage, our food bill is our second biggest expense every month.... so if I can save money there, it is a big thing!
Anyhow, it can be done... good luck with the new house AND with your Disney savings!..................P