We're also looking at upgrading our Aerohive infrastructure, which is running a mix of 802.11n/ac access points, some over a decade old. It's been a mix of hallway and classroom deployments, and I'm pushing to get one AP per classroom (plus a few for offices, gyms, cafes, etc. as required). I'm hoping Ubiqutiti releases their 802.11ax stuff soon.
OP, just curious, why do you think you can reduce your AP count from 70 to 30? No new bands have been introduced that increase the coverage, and in 2019 coverage is rarely the issue, but capacity. You almost never run APs at full power these days. Just because you can get a signal, doesn't mean your performance will be good.
