For over a year, (and several hours of posting time), I have been in a plot not to answer your question.
Get over it!
As the others have stated, we read all the questions and respond when we think we have something to add. I have been a little distracted the last few days and have not been on the site as much as would have liked.
You posted this question and an hour and 15 minutes later, you are upset that you do not have an answer?
This is not a live chat room with everyone waiting to answer questions.
Now with that said, I will give you my opinon.
I think that it would be a mistake to attempt to do this. What you are going to have to do to make this work, will be more costly than to stick build an addition.
You could build it on a frame of on old mobile home for when you it move but, I think that a building mover could move it just as easy if you built it on a foundation.
Find out what you park rules are and decide.
ps. Please don't tell anyone I responded to your post, I don't want to get kicked out of the club!