So, alternative take. If you have a home PC would you be better upgrading it and getting a cheaper laptop for more basic use?
Basically do you really need a mobile work horse? If you're doing video work then you may be better with a graphics card or CPU upgrade £ for £. Do you really want to be editing videos on your sofa or in bed? It doesn't seem like the easiest of most productive way to work in that particular use.
You can also stream any game from your PC to a laptop (or other devices) using Steam or other streaming tech. The pc can be on but with the sound and screen off, while you're elsewhere streaming a game.
So maybe a PC upgrade and a shared basic laptop for video and internet would be enough? The only downside is if you genuinely think you would want to do full on video work on the go - out of the home or abroad for example. Then it makes more sense.
But if this is more talking yourself into buying an expensive toy, there may be better toys to be had.