I did check the hardware, and it was listed as Linux compatible, with no indication on wireless firmware being an issue. Whilst looking into Trisquel I either didn't see or didn't notice that all the people there using and recommending Thinkpads didn't use the default wireless card.
It was only on looking more into Linux-libre that I discovered it doesn't just remove non-free firmware, but actively refuses to load it even if you install it separately.
So I'm going with Debian - still got some more setup to do today, but not oversleeping like I usually do means I at least have a bit of time.
EDITED: 3 Feb 2017 11:36 by BOUGHTONP