One possible option would be to try something that's not downtown. A couple of years ago we stayed at the Springfield Suites hotel...it was very clean and comfortable. I don't know what would be available for the kids, as the ones with us were teenagers and they pretty much lived in the swimming pool! I ran your dates and it looks like about $125-$130 a night. The sofa was a trundle bed.

Anyway...might be worth considering

https://www.marriott.com/reservation/rateListMenu.mi?defaultTab=prepay