lake house in muskoka for 3 couples next month, anyone done this type of trip

eh so were canadian, based in toronto, and we just locked in a lake house up in muskoka for a long weekend with two other couples we met at a club in the city. its a proper cottage on the water, dock, sauna, hot tub, the works, sleeps 6 comfortably. weve been once before with just one other couple and it was incredible but going from 4 to 6 people feels like a real jump. specifically wondering about the sauna situation because thats a whole different intimate vibe than a hot tub. and the cottage has a screened porch overlooking the lake which honestly feels like the best play space ever but its also pretty visible from the dock area if anyones out fishing. anyone done lakeside group trips in muskoka or the kawarthas and got the lowdown. also do you bring your own bedding or trust whats there