I've used 90w, 60w, & 45w adapters with my machine that came with 135w standard. It's probably not recommended, but it depends on demand. I think 135w for mine is the maximum, I've never had an issue other than the initial warning from the BIOS it's not the original charger.
Ask your boss to also give you a travel Thinkpad.
The new X13s (with Snapdragon) comes to mind.
It is supposed to have terrific battery life (28 hours...)
Lovely day for a Guinness! (The Real Black Stuff) But I actually prefer Murphy's from Cork!