You and I have some similar elements in our lives (self-employment, disability concerns, etc) so although you aren't rural, some of this might be relevant. I had only intermittent service for three years previous to my newest life. That was not ideal, but okay.
I implemented workarounds:
*type stuff (onto laptop, yes) then take laptop to internet and hit send on everything
*ensure regular backups of work, because the cloud won't be doing that stuff
*yes, let people know I had slow response time to all forms of messages
*ensure laptop has DVD/CD drive, or get external one (lots of new ones don't have one)
*excellent noise-cancelling earphones for internetting in public places
*if privacy is a concern (e.g. confidential client stuff), something to make your screen more private -lots of coffee shops, libraries, etc, have seating arranged such that your screen is visible to all; I don't like that
Some places it was trickier, making me glad I have great service again:
*being on hold - I didn't have cell minutes for that; internet allows the up-to-two-hours some businesses need to answer
*when sick/injured: lying on a rec centre hall floor to send out my work sucked; having no contact with ppl sucked
*emergency-type services: since I also had little to no cell reception, sporadic internet was an important aspect of the plan
*managing all communications: I hate when ppl talk on phones in shared spaces, so I generally don't do it. I find it very helpful to have internet in a place where I can talk on a phone, while accessing documents, websites, my calendar, etc, all at the same time. Ditto when child's supports insist on doing video calls.
In your situation, I might label home-internet a near need.
