> Isn't there a FOSS alternative floating around

I don't know of it, but there has to be an alternative hardware option

> License-free

If you are speaking of the frequency band, that's open to any radio protocol that can operate in the frequency so not specific to LoRa it just so happens that they developed the hardware to operate in the 100-1000mhz range so it could be made free depending on the region you live

> low power draw

I personally don't think LoRa devices are power efficient but I had hands on experience with other devices short of SDRs, but I think most developers assume the radio is going to be idle or in receive mode which consumes under 2ma iirc, but on maximum transmit power the Semtech units consumed about 45ma iirc in my testing. It's been about 5 years so I could be off, but we only fit enough battery for 4 hours with most of the radio time spent transmitting.