I'm planning a trip with my fiend and our sons for early July. I did the west side up around to Mattawa and then north to Temiskiming last summer. I can share some tracks that I have and am working on.
I've done this tour around the park 3 or 4 times over the years. We left from the Bancroft area each time and either went clockwise or counter clockwise around the outside of Algonquin Park. Minden area is tough. The Haliburton trails are ATV focused and have lots of water holes. Same goes for the stuff Yawny mentioned earlier near Kearney. ATV trails = water holes = mud and deep ruts The area from Pembroke thru Chalk River and Deep River is sandy and constrained by the Army base. Still nice though. Our lodgings have been: Dinner Bell Motel and Restaurant on Hwy 17 near Bonfield. Hillside Inn in Pembroke Super 8 in Huntsville Valois Motel and Restaurant in Mattawa This is a 4 day ride usually. Its nice to get a motel with some sort of restaurant attached. We always arrived late in the evening but the Northerners are great hosts and always accommodating. If you want to make it even longer and adventurous you can run the VMUTS trails near Mattawa and then get back south thru North Bay. Not sure how this all goes with Covid restrictions. Not sure you can even get a motel or find an open restaurant. Its a great ride. Bring tools, spare tubes, brake pads, sprockets and chain (inside joke) etc. Bring your A game.
Listen to ARP guys. If he says an area is tough, believe it. The only thing I can add is the last time I stayed at the Super 8 in Huntsville it was absolutely disgusting. A total opposite from a few years before. A complete dive now with it's own multi gender greeter, that was the strangest human I have ever witnessed, hanging in the lobby. I will never stay there again.