Trying to research this a little bit. This has NOT happened to me but I am studying a possible worst case scenario here. As per the thread title what would the "math" say about immediate power loss after clicking send in Trezor/Suite or in Electrum? I was wondering if it is possible that such a transaction could get hosed in a way that the funds would get stuck or worse in the wrong place? By stuck I don't mean a couple of hours to work itself out but a complete stuck scenario? Even if I always use a Laptop the router could lose power at exactly the worst instant in time. Just asking?

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I would love to hear about and read any links on this subject.
If a device has both internet connection and private keys, it would be able to both sign and broadcast a transaction on that device. Basically creating a transaction , signing it with your keys and then broadcasting it relatively happens simultaneously that's if we consider the couple of seconds it takes for each of them to happen.
Basically if the transaction was created before the black out, it's possible that when you get back online your device may still render the signed transaction valid else nothing happens.
Basically coins only leave your wallet not only when a transaction is broadcasted but when the broadcasted transaction has been confirmed.