Video throughput is boring. You don’t need an nvme for that. Unless you serve many, many users in parallel with different streams. And reading won’t stress the nvme anyhow.
Here are some figures with a Crucial P3 plus (headless mode):
You can see the system in idle state at about 550mA, in heavy use (write) you are between 600-900mA with some minor spikes (probably when the system clears the buffer caches to the SSD). So this is a plus of 50-350mA, so hardly 1W in addition to baseline Pi5.
Of course you somehow need to have a minimum of ventilation. Setting up the system vertical should probably already be enough.