I teach online. If no wifi where I am staying, I can go into town to a library or fast food restaurant to use my laptop.
But, my class sites are also accessible to me on my smart phone so I only need access to a cell tower. I can grade, moderate the discussion forums, open and close modules, and answer emails. I can even do video conferencing with a student from my phone. Handled a three way conference call with me, a student, and my dean once while fishing on a boat on Lake Erie
It is really handy in the summer when I am not on campus as it enables me to teach summer session classes. During the Fall/Spring semesters, I can keep up with the classes when we camp on the weekend.
I facilitate 7 days a week in an online class with a required a 24 hour response time, and need to respond to my face to face students within 48 hours,