6.6 kW sounds quite excessive for a trailer. That's what I have on my 3200 square foot home.

New trailers actually come with solar panels already on them. They have a metal framework built on the top of the trailer and the solar panels are installed on this framework. For retrofit, it should be feasible to have solar panels installed in a similar manner.

Regarding building a framework and tearing it down each time you move, it would be possible and plausible if you move less than once every 3 or more years. My guess is that it would take at least half a day to tear it down and careful packing to keep the panels from breaking while moving. It would actually go up quicker, the connectors have tabs that connect (actually they are not meant to be taken apart) when put together and these connectors would be time consuming to take apart.

While it won't be 6.6 kW, I would suggest putting as much as you can on top of your trailer, done professionally, and then use hookup or generator for electrical needs above that.