Hi Bryan, I cannot speak re Portugal - different systems, different police, but in Spain an obvious pilgrim seems to be given some leeway - go into any large town and get off the roads down to the main river and you will see how many immigrants live in tents, so a problem with a pilgrim staying one night? Would have to be a very bad tempered policeman.
You are already a wild camper so know how to find safe and hidden spots .. when to camp, when to leave - on the
Camino Frances there are quite a few refugios that are happy for you to tent overnight maybe there are in Portugal too (if still open).
Mind you .. watch out for the weather, is weird down that way at the moment!
Re showering .. it isn't necessary, it is only a habit fostered by a multi-billion dollar profit industry. I don't take baths and probably shower only two times a year.
The skin is the largest organ of the body and is specifically designed to have a living protective microbial landscape on it - every time someone showers, especially using gels, they strip the skin so that it has no protection at all, nor can it give protection to the body.
We produce smell from only three places - armpits, groin, feet ... so all you need is a flannel, additive free soap, and some water (which doesn't need to be hot) .. soapy flannel those three areas, rinse .. rest of body just rub with the wet flannel. You will never be smelly and after a couple of months your skin will always be healthy and silky smooth.