Smallest possible machine for web programming?

I use 15 inch MacBook Pro for work. My personal machine is 13 inch MBP. I like to stop by coffeeshop and work on personal projects until traffic dies down. However, carrying both machines at same time is a bit cumbersome. I could leave my personal machine in the car but prefer to keep it on my person in office. It gets really hot in summer and we don't have covered parking always.

So I am looking at smaller personal machine that I can carry with me to work. My personal projects are mostly web based, I have various VPS for dev work.

So here are some options:

1. Surface Pro is the first option that comes to mind but it is almost as big as 13 inch MBP.

2. 10.5 inch iPad Pro is next option, not perfect setup but many blog posts about using it as main dev machine with certain apps. Bit expensive for what it is though.

3. Pixel C - 10.2 inches. Looks good but older and storage options are limited.

3a. 8-10 inches Android tablets (not sure which one). Again these will be limited but it seems people are able to make them work. Will need to buy a keyboard, don't see many clean solutions like iPad pro.

Anyone here has any suggestions?