Re: how do i make it warm
There's an old saying, I'm sure you've heard of it: " A penny saved is a penny earned"..............well, this version goes like this : "A BTU saved is a BTU earned"
Insulate everything to the max:
use plastic sheeting to add an extra layer to overhead hatches and portlights
add sheet insulation to the hull where ever you can
seal off dorade vents for the winter (assumming you're not burning fossil fuels)
you get quite a lot of cold radiating from the bilge so use sheets of bubble wrap to help out
after all that, make sure you gain all of the solar heat you can. You can even make a solar oven and use a computer fan/ducting to circulate the heat.
extra clothing layers and a good mummy sleeping bag and you should be good.