I did that for years with great success. But it does depend on the nature of the work; for the past year or so I've been needing to run multiple VirtualBox VMs, a heavyweight IDE, and other memory-hungry desktop apps.
Cloud servers aren't great for interactive work like developing/debugging in an IDE or running a VM of a graphical OS (windows). I still use remote servers when I need real CPU/memory horsepower.
Yup! My ThinkPad 25 might not be super light but this side of 2011 it's the only seven row layout so it'll do and it's 3.5-3.9lbs depending which battery I take with me. I have a server rented at Hetzner which few laptops could match and none you want to haul around if you don't drive.
This way your lap doesn't get hot and your battery doesn't drain. Plus, you don't have to carry around a paving slab.