Late to the party here. I live on Quadra. I see you are leaning towards the option to circumnavigate Read. That’s what I would have recommended.
It is roughly 31 NM starting/ending at Heriot Bay to go all the way around Read Island. The map I linked to breaks it down into 4 legs. Those athletic (and masochistic) types could do it all in one day, but that would be 10+ HRs paddling. You could do it in 2 days with a rest day between. I recommend doing over 4 days (3 nights), which allows you to stray off course and poke into places like Von Donop Inlet (on Cortes) or the islands around Surge Narrows.
You can go clockwise or widdershins; it is the same either way, but you would do well to consider the tide tables and wind forecast to put conditions in your favour. On this side of Quadra, the tides flood north and ebb south, mostly.
If the tides work out right, you can launch from Heriot Bay and paddle on the flood north to Freedom Point (8 NM), lunch there, the paddle through Whiterock Passage at the slack, and ride the ebb north (yes, I said that) to North Rendezvous Island (6 NM) to camp there. It’s a tidy way to get almost half your journey done in 1 day. This is your best option as well if there is a SE wind pattern, since it limits your exposure to getting across Heriot Bay to the shelter of the Read Island shore. Do take care not to lollygag too much on your way up as it is no fun arriving at North Rendezvous at low tide. At high tide, the water laps at the foot of the campsite which is much preferred to hauling your gear and boats across the oyster beds.
If the wind is prevailing NW, going counter-clockwise is better. You launch from Heriot Bay, paddle up to Big Breton Island, head over to Viner Point, and then follow the Read Island shore up to Whale Passage camp (aka Frederic Point) or one of the camps in the Penn Islands. Again, it is best to time your arrival at a mid to high tide. Landing at low tide anywhere in the Discoveries will put a damper on anyone’s day.
Bring your own water. Full stop. Yes, there are streams to be found on the shores of Read Island and surrounds, but this has been a very dry year and there are no guarantees any of them will be flowing by the time of your trip.
I very much recommend to anyone in the club considering trips up here to look to the shoulder season months — April/May, September/October for the best experiences. By September the crowds will have largely abated. The days are long enough to avoid paddling in the dark. All of that said, review my map (or the BCMT map) for your camping options. North Rendezvous Island, South Rendezvous Island, and the Penn Islands are all popular sites and you may arrive to find them full. Know your options and give yourself time to paddle on if necessary.
You can email me if you have any questions. If weather, tide, or a desire for solitude affect your plans, I can point you to other places to paddle that would be a better fit.