Is there an internet-enabled e-ink thing you can type on? Or hook to a peripheral keyboard? ‘Cause the more I think about it, the more I find the thing I’d like most in a portable computing device is the ability to work on my writing outside in the sunshine. That’d be boss.
What I think you’re looking for is this: https://www.kickstarter.com/projects/adamleeb/hemingwrite-a-distraction-free-digital-typewriter
Although the reviews are somewhat circumspect in their praise.