@drrich2 thanks for these suggestions! Ideally, I'd love to find an AI someplace or a nice resort that also has a kids club and/or things to do for kids. We also have a 4-year old, and I'll be staying back with him while the others dive.
Sunscapes Resort Curacao might do quite well for you; it's where my family stayed in the ScubaBoard Surge trip report I linked earlier.
Traveling with 2 adults and 4 kids is really gonna run up some air fare, then there's the course cost for 3 kids. I have no idea what your finances look like and I'm not asking, but acknowledging that for a lot of families, the bill for all this would be a big hit. Unfortunately, you guys live a long way from oceanic places with warm water and very benign conditions like you might want.
At some point, you might have to consider air fare impact on trip cost. Southwest Airlines' 2 free checked bags and modest 'Wanna Get Away' fares make round trips to Ft. Lauderdale pretty affordable (or did when I went).
Last year, flying to Bonaire Wed. - Wed. instead of Sat. - Sat. made a huge difference in airfare (on my Feb. 2022 trip).
Cozumel is a well-known quality budget dive destination, but known for drift diving...and I'd want to know the OW course dives wouldn't be drift dives. If someone good trains there and can confirm that, you'd have A.I. options and an affordable destination! Just in case anybody can confirm Cozumel would work for you:
Tres Pelicanos & Casa Mexicana, Cozumel Sept. 2018 Report -
Tres Pelicanos/Casa Mexican Trip Report Sept. 2018
My Research Notes from Planning Cozumel Trip -
My Research Notes from Planning Cozumel Trip
P.S.: There is some limited shore diving in Cozumel. Off the top of my head, Hotel Cozumel, Scuba Club Cozumel, Blue Angel Resort and Aldora Villas all have something to offer. From complaints about food, I wouldn't pick an A.I. option at Hotel Cozumel unless you read up on it for yourself.