Lots of ways to cut the budget down...
Breakfast - In room, packaged muffins, protein bar or cereal bars, fruit cups, juice boxes, instant oatmeal and/or grits, cereal and milk... This way they we not starving, and I found that with all the excitement they really did not or would not eat alot when we were sitting down for meals... So at least you got something in them to start the day.
Snacks - Bottled water - yes and yes - in the parks... protein bars, mixed nuts, gold fish crackers, crackers chips, cheese sticks, juice boxes... I had a small collapsible cooler that I have used for years and years, I did have to replace it right before the pandemic. It's was like a large lunch bag, to go along with this, I have these bento box style plastic container that I bring along that have these gel ice packs that attach inside, along with a yeti gel ice or whatever brand to put into cooler, I could bring in cheese sticks, drained fruit cups, pickles slice's, a couple of juice boxes, couple extra bottles of water and a couple canned soda... I have brought along "lunchable" for a quick snack... when the kiddo's were little the cooler went under the stroller, so out of the way... I would say pretty much everything stayed cold or cool for about 6 hours... by then it was all eaten so it worked for us. I also have insulated lunch sack, that fits into the backpack for just a couple items...
Bring all your OTC med's with you... this stuff in the parks is crazy expensive... Stomach med's cover your bases, nausea, indigestion, heart burn.. Tylenol or Ibuprofen, neo-to-go and band-aids with as assortment of size's ... make cover everything for adults and kids both..Double check your prescription med's as well make sure to bring only what you need and maybe a extra day or two... I almost forget sunscreen... good sunscreen is important..
Bottled water, soda, adult beverages, juice boxes in room, drinks in the food courts add up really fast...
Look at the menu's and kinda see what your family will eat... There are alot of reasons... first you don't want to go into a place and realize that they really don't have what your family will eat, especially right now with the supply train and the shortages... So being prepared is a time and money saver... Next up.. Meal sharing which is easily done, even in TS restaurants... just ask for extra plate, and don't forget to tip as if you were not sharing. Appetizer's are a great way to save money, there are a few spots that offer a large appetizer plate or tray, in most you can switch out or add a side of chicken tenders, or maybe a side salad...
Kids meals are they really necessary? ... You can share off your plate, or order a adult meal for them to share...Plenty of times we shared meals, with our kids, and now grandkids... still doing that... One thing is normally we don't order dessert at a TS, we like to sample the treats in the park...
Give the kids a set amount for souvenirs - and once they spend it their done - We would buy them each a T-shirt on us, then give them a set amount...you will be surprised how they really think about what they are buying when they are spending "their money".
The biggest saving is of course transportation really look around for flights and if your driving scope out the gas cost around you..
Resort, and Hotel are costly - so knowing what your family likes are they more into nice hotels for amenities nicer pools with a slide, kids activities, spa, golf course and you are planning on using them... or are you a rope drop to fireworks family, only needing a place to sleep and shower... or are you somewhere in between... really look at what you need verse's what you want... can help you make the right choice...