Honestly, guerrilla growing outdoors can be beyond horribly frustrating. Even if it's in your backyard and in perfect conditions the great outdoors can be frustrating. People will find your plants and steal them no matter how careful you are. Or worse, law enforcement is involved in finding them. And when it's not people destroying your plants, it's animals. Everything on four legs seems to love eating pot plants. Especially the cute animals like Bambi and Thumper. And when it's not animals, it's insects. Every insect in the area will either zero in and start eating your plants exclusively or laying eggs on them so their demon insectoid offspring can eat your plants as soon as the buds start forming. And when it's not insects, it's weather. It will either rain for the entire season and flood your plants... or it will be drought. There will never be a perfect season with nothing threatening or chomping on your plants...
Yes, when the great outdoors cooperates *and* you have the ability to really care for the plants, the payoff is beyond excellent thanks to the sun...
But really, do yourself and your friend a favor and get a nice little cabinet with some decent lighting indoors and be content you can visit and care for your plants whenever you want to give them whatever they need. Because if you have to go through any crazy steps like growing in hidden holes and can't use the sun *on top of* everything else that threatens plants outdoors... it's only headed towards heartbreak if you get anywhere at all.