I have a foldable, transportable 120W solar panel in my RV trailer.
Once the compressor fridge drained the trucks battery so low that I could not start it, but battery was not dead.
I attached the solar panel to the battery in a not perfect location under trees, but with filtered sunlight and after about 1 hour the truck cranked.
It would be easy to calculate the power need, just add all max amps of the connected devices and multiply with 12V to know how much Watt the solar panel would need to run all devices under worst case max load. Most/all devices rarely/never pull max Amps, it can be much less.
However, it could be difficult to reach 100% autonomous running of house needs, but it will slow down battery drain considerably on a sunny say.
For autark use need a good quality rigid 120-200W panel would be best, if only battery trickle is the need a much smaller panel will do the trick too.
Flexible panels are working good and are barely visible but most of them have less power than a rigid frame panel who are cooling the back thru air circulating, but they are ugly. Also, flexible panels must be glued on well to avoid that they vibrate as that damage them prematurely and that makes them difficult to remove and will probably damage the hard top.
I personally would go with a rigid frame on with their brackets glued on with 4200UV/5200 as the adhesive can be removed if 24/7 installation is needed, otherwise a small, removable one if theft is not a issue.
I had in Costa Rica some really small panels from Walmart to attach on the cigarette lighter and they did the trick to keep the car batteries charged. However I would be careful with cheap ones, if the charge controller inside is overloading the batteries it will damage them and produce hydrogen what is not good as we know from the Hindenburg.
Investing in a good solar charger will give more power and avoid damaging the batteries, boat or people.
Victron is my favorite brand for solar panels and chargers
Chris