Hi Daniel, welcome to the forum.
I have a temporary track installed on a similar deck at the back of my house [see pic], it is about 9 feet wide and 17 feet long. I use R3 curves and have at present only one short siding. I use DC only.
One issue I do have is the noise created by the trains. I have to turn off any sounds that the locos electronically create [I have had lots of help from forum members re safely pulling locos apart to install switches etc] plus I found that some locos and carriage combinations make more noise than others. Plastic wheeled vehicles are quieter but that is impossible for locos obviously. The sounds seem to be generated between wheel and rail mainly, higher speeds make things worse.
I have found heavier locos make less noise generally, some LGB ones are ok, some of the other brands plus lighter weight LGB ones can be a bit noisy.
If the ambient sound is reasonably high and covers the running sounds then you should be ok, it all depends on how close and tolerant the neighbours are I guess.
I have considered putting soft plastic pads under the track but haven’t experimented with that.
All the best and enjoy your trains.
Monty