re: Outdoor speaker setup

All the things you just mentioned plus the fact that SONOS doesn't make outdoor rated equipment. I love SONOS it's a great product but NONE of their speakers are outdoor rated. You could do a connect amp and run a pair of outdoor speakers if you want to have an outdoor SONOS zone. But giving the OP has an odd shape outdoor space two speakers aren't going to cover that entire area. It will either be too loud where the speakers are located and not loud enough where they are not.

Bose makes their version on the SONOS connect amp called the SA5. It has more balls than the SONOS and can handle 2 pair of speakers. This IMO would be the better option given the OP space. I would go with one SA5 and two pairs of Def Tech outdoor speakers. This is of course if you don't already have SONOS in you house. If you have or only want SONOS then just bite the bullet and buy two connect amps or one bigger dumb amp and a SONOS connect.