Is there anything small which can run Debian?
How small is "small"?
My old MSI Wind U100 netbook ran Debian perfectly, i.e. all the hardware was
fully supported, including 3D graphics, with no need for any binary
blobs (according to "vrms" it was clean, except for those pesky
emacs-common-non-dfsg packages ;-). The only tweak I'd had to do was to
replace the mini-pcie wifi with an Atheros one (the original wiki
worked more-or-less OK with a firmware-blob, but the driver was in
"staging" and had a few issues).
IIRC there were many similar machines back then (you just want to be
careful to avoid those machines with the gma500 aka "Poulsbo" graphics,
for which support is problematic).