What about an Android tablet running a custom ROM without GApps flashed, and an adapter for HDMI? There’s a handful of widely sold tablets that also have a decent development scene and are cheap second hand. Check XDA forums for various models before deciding which one to get
I bought my ThinkPad a fair bit before yours, but I can’t imagine replacing my T450s either. The dual batteries, TrackPoint, and sheer number of ports is something most modern laptops just don’t include. Ten years old and still running beautifully thanks to Linux (Fedora 41 Gnome). If I do end up leaving it, I’ll be getting something a few years newer, like the T470p. But it’s a no for new ThinkPads :/
New New Mexico and Old New Mexico