Around 1996/97 timeframe, you could fit a kernel and userspace. I remember building a 1.44 setup that booted a compressed kernel and had enough user space tooling to bring up telnet, ftp, and the radio stack to drive the long haul radio cards (we were replacing JNOS [0] IIRC at an ISP ). Even had writable space at the end of the floppy (the kernel etc were readonly) to write overrides of the config; poor man's overlay I think, but it is rather a long time ago.
Given we were working with 286 era hardware (maybe 386?), I'd be surprised if ELKS doesn't fit on a 1.44. Indeed, simply looking at the downloads page linked from the original link would have answered your question.. [1]
0 - https://www.langelaar.net/jnos2/documents/about.html
1 - https://github.com/ghaerr/elks/releases
