Are you sure the Satellaview was available for the Famicom (NES)?
I was wrong about the satellite integration [1]. It was dial-up.
I'm almost certain I remember a similar effort for the Game Boy Pocket, though it might not have entered the market.
[1] https://en.wikipedia.org/wiki/Family_Computer_Network_System
Even though accessories were required, you could probably do this with both the N64 Disk Drive or GameCube network adapter. Both were network interfaces that still dispatched to the underlying system.
The N64 Disk Drive [1] would be a fun case, because the storage medium is a glorified floppy disk drive. It does connect over a modem, so there'd be some fun middleware.
The Super Nintendo had a network adapter as well, and both the NES and SNES [2] had satellite networking adapters in Japan. IIRC, there was also a network adapter for the Game Boy. I'm not sure how or if those would work, or how much control was surrendered to the hardware/software of the network adapter itself to let it do all the driving.
[1] https://en.wikipedia.org/wiki/64DD
[2] https://en.wikipedia.org/wiki/Satellaview