While not exactly a cottage, my family had a sailboat for many years. It could sleep 4 people and had a small dining table, stove, sink, head (toilet) and even a TV. We'd sail on Lake Ontario for a few hours and sometimes went to other marinas and spent the night. Marinas typically have shower facilities, BBQ's, and on-site restaurants or walking distance away too. So the boat functioned as a floating and moving cottage.
Like a cottage, boats particularly sailboats are a lot of work especailly preparing them for the winter. Maintaining the engine, repairing any hull and keel damage, draining water tanks to prevent freezing, and covering the boat to prevent ice build-up. Over the years, we improved our processes to make them easier / faster. The boat was docked in an Etobicoke marina so it only took 15 to 20 minutes to get to "the cottage." I could even take the bus if I needed to.