I have taken my Tanzer 22 up and down the west side of Georgian Bay a couple of times and been in the North Channel 6 times on the Tanzer and my Sandpiper 565. I agree that the North Channel is the better idea, but there are places to go on the west side of Georgian Bay.
One thing I would note is that 3 weeks is not a lot of time in a
small boat on big water. There are frequently 3 and 4 day stretches of high winds and waves that prudence and comfort suggest staying put is the best course of action. For example, last season I waited in Wingfield Basin for 3 days waiting for better conditions. A few days later it was wild coming into Collingwood too.
My point of the above is that if you can
trailer your
boat, the west side of Georgian Bay would leave the possibility of bailing out at one of the towns and having someone come retrieve you and the boat with greater ease than somewhere in the North Channel would.
Of course if you have
trailer abilities, another possibility I could recommend is to take the
ferry across to Manitoulin and launch at Spider Bay Marina in Little
Current. This will cost quite a bit, about $300 each way, but it gets you in and out in a day each way guaranteed, as opposed with taking your chances on
weather coming up Georgian Bay.
I also very much recommend that your main has two reef points and that you have a small
head sail in the 50% size range. Oh and jack lines and harness
gear.
I assume from your original post you are new to sailing, not just new to your boat, so forgive me if you indeed have years of experience and the above is somewhat superfluous.