Should I buy extra parts for ITX build?

I don’t really need any hardware upgrades, but I hate how much space my atx build takes up. I’m basically reorganizing my room and I think downsizing the pc build could actually free up a lot of unused closet space in my room. Looking to spend around $300 on a new case, psu, and mobo. Another pro would be then I’d have enough parts to build two PCs, and I have an extra TV now. So I’d like to set up entertainment room somewhere in my house using the extra TV and spare PC. I feel like having a PC hooked up to a full size TV with Bluetooth keyboard and mouse is the ideal multi media station. My mom doesn’t like the idea of having a “tower” (the atx build) but I think I could hide it. Another problem is I use Ethernet so I know the atx mobo doesn’t have WiFi or Bluetooth.