Megabytes, a thousand of which make a gigabyte. Chrome in my machine right now is taking over one gigabyte of memory, that alone is using more than 8 times what OP wants the whole system to. It's definitely an ask for low memory, almost embedded levels of ram.
I imagine you could find a lot of options. Just a quick google turned up ThinStation, which only needs 30-50MB if storage and 64MB+ of RAM. A bit outdated, but should work fine.
You could also make your own OS with LFS if you want to optimize it to the extreme.
Thanks that looks pretty good. Ihad searched and found nothing. The internet is full of folks who "just get X linux distro and write a bunch of scripts"
It even supports Spice. Only thing missing is moonlight support !