Sounds like you have a lot of cloud dependent devices to deal with. I know @ogiewon can help you with the Alexa method going. He also wrote an HE driver for Google Assistant Relay which you can use for TTS to a Google Home device, but you can also use it to silently control devices via Google Assistant. That doesn't require you own a Google Home, you simply need to setup a Google account and you use Google Assistant, which you already mentioned you don't use, but to be honest I don't really either. I almost never talk to my Google Home Mini. It just does certain announcements for me and the Google Assistant Relay driver for HE silently controls some cloud devices I have, for which there is no option in HE at this time.
It does require you set up a standalone Node.js server on a Raspberry Pi or spare computer, so that really depends on your skill and comfort with those sort of things (although it's not too hard actually). The Google Assistant Relay is quite valuable to me. I'm doing some things that just wouldn't work well via IFTTT as the latency is too slow for a few of them (not all IFTTT tasks are slow, but some are really slow). Google's cloud on the other hand is really fast and reliable, across the board.
Anyway, here's a post that describes a few of my most recent uses for it.
