Hey, I'm new here in Freelancer, and this would be my first job. I think that this work can be done with Tampermonkey as you said in your description, I'm quite good in Javascript and JQuery. I can provide you the script for your task.
My idea is:
1) refresh the page every 5/10/30... s (whatever you'll choose, of course you will able to disable/able the autorefresh),
2) when the survey is available it will appear a notification box on your browser,
3) while you're filling the survey box the script will save the question and the answer in local Storage (so max 5 MB of data I think),
4) the next survey that you will do, the script will fill automatically boxes with the SAME question.
All I need is the site where you do the opinion survey, the surveys website (or just the HTML page, because I need to know how the webpage is structured).
I know that is a very "basic" solution for you, but is cheaper :)
Hope to hear you soon, have a nice day!
Lorenzo