If you’re just aiming for a bigger base, it might be possible to throw together in CAD software and 3D print or CNC mill, especially if by “base” you’re mostly meaning the Bottom Cover / the aluminum frame on the bottom of the device. I haven’t seen any projects aimed at specifically at this yet though so there’s not a drop-in solution I can recommend.
As for adding ports… the fastest way to that is probably a USB-C hub, to be honest. I’ve seen some people recovering USB 2.0 ports through breakout boards of certain components, for example this one recovering a USB 2.0 port by sacrificing the Fingerprint Reader and replacing it with a “normal” power button
There’s something of a master list of a bunch of concurrent projects here although I don’t think they’re all of them.