Are you planning on reaching out to NGO or Government with these solutions, or do you have a more kind of grassroots/non-violent activism approach to the whole thing?

I guess you might need to consult lawyers and look for permits, if you want it to be a more permanent solution, but just starting to do it as some kind of grassroots activism could also work since you probably would get a lot of sensational media coverage.
And that could be helpful.

But then after that you would have to play by the rules, if you want to provide a more permanent solution and be taken seriously and not have your temporary house trashed/removed by law enforcement etc ...

You know one part of my training was to build huge mobile refugee camps, this was when I was enrolled in the civil defense, (a while back). And then we built a whole bunch of mobile refugee camps real fast, as a part of the training, Im sure this could be a good time to put these skills to use, considering homelessness in the world looks like a real emergency right now...

I hope you get the funding you need, I will send you a small donation.

/FF