I understand your challenge. I have been poking about in these waters for 3 years and I have not even scratched the surface. Yet I have found some beautiful places to explore.
What I have found is a trip with about 5 hours or less transit and the rest spent exploring works pretty well. At 10 knots the would be about 40 nautical miles. The evil truth is you just don't average 10 knots. It is always somewhat less.
Your bus vs convertible is a pretty good analogy and I suspect you would favor the convertible (I hear speed boat). While you would get to your location, a speed boat would not have the home comforts of a bus (think VW camper van - sailboat).
That is not to say one is better than the other. A fast speed boat and a stay at a B&B can be very entertaining. And while speedboats might be fun to anchor for lunch, not sure they would be too comfortable in a winter blow..
This is my friend Les, Myself and behind the camera Ward during our "Extreme Winter Cruise of 2019". The dock at Saturna Island. We overnighted is a warm cabin and completed a 18 day cruise that took us from Everett to Vancouver BC (for the boat show) to Seattle and back to Everett during the first week in February. I know not a bathing suit cruise but lots of fun. Lots of exploration. More than a weekend experience. Possible on a sail boat.
You should check out the power boats for sale around False Creek Harbor and Granville Island. Explore the boats. Sit at the helm, imagine waking up and getting up in the middle of the night, test the head, discover where your seat would be to sip an evening beverage, or a morning cup of coffee/tea. Once you have done that you will be more ready to make the decision.