Ebbie, I haven't said anything, but have been reading along with interest. I think I remember you said you'd take your dog with you. I have great concern for you and even greater for your dog. What would you do if something happened to him? Someone tries to steal him or cuts him loose while you sleep or a bigger dog attacks him? I don't know if any of those is likely, but I'd sure want to know before taking my old pup out for the night.
After reading everything, I'd say I agree with those who are saying you do not need to "walk a mile in their shoes" in order to continue with your compassion and aid to the homeless. I think I understand your consideration of doing this, but hope you do not do so.
This spring, my son came close to being homeless; he was a step away but for us finally relenting and letting him stay in our backyard for awhile. He is fine, now, but there were life choices he'd made that put him in that situation. I'd hate to see anyone take than on for any reason other than the most dire circumstances and even then I'd hope they could find some help such as your shelter provides with you there to greet them.