Trying to connect to a city wifi AP half a block and 6 stories away. Did a preliminary test with an old asus rt-n66 running Tomato, and if the signal strength is to be believed (-56dbm / -85dbm noise), this can be a viable solution. The AP is using a ruckus 4x4 wave2 qualcomm.
While I've seen some tri-band (dual 5ghz) routers, the options are far greater if using a secondary router for the local AP. In the used budget market, this seems to limit choices to mt7621, ipq8064, and ipq4019 devices. That or defect back to broadcom and tomato/ddwrt, although I'm not sure if it'd be possible to use passpoint in that scenario.
I don't have a clear idea of max possible bandwidth, but am assuming it to be around 300-400mbps from this distance based on performance from the n66. Will obviously have to forgo sqm to have any hope of achieving this.
Of the socs, I'm not sure how/if offloading would work in wireless client mode, but is there an ideal one out of the bunch (or one I'm missing)? I've found a few candidates for each soc in the $30-40 range used on ebay.
Also curious if passpoint/hotspot2.0 performance/support would push towards one particular soc (eg if it precludes offload).