I suspect that 90% of any work that I did on my boat(s) over the years were inside of the boat itself.
I never thought to do anything else other than leave it on the trailer, inside of my garage ( damn HOA). I keep front and back garage doors open, and I often add a fan or two directed at the area in which I need to do the work.
I do put a full size 6 or 8 foot step ladder on one side. I haul a lot of tools to the boat before even starting, but I am always crawling back off and on to get something else.
I also bring a light or two, since inevitably, I will be working under the console or someplace that is dark.
Having a cooperative wife nearby (shouting distance ) to hold/grab/fetch something is invaluable. A nice dinner out is only fair for your friendly helper!
richg99