It doesn't get that cold here in the South of France, maybe 3/4 months and that's it, we don't get any of that white fluffy stuff.
But as I get older I get softer and any fool can be uncomfortable.
Our 42' is partially insulated, as soon as a part of the hull is exposed for access for any reason we insulate it.
We've also insulated all the hot air delivery pipes with 'snap on insulation' sleeves which make a considerable difference to the delivery temperature.
We fitted a 8 kw Planar diesel fired hot air system on our boat and we're very happy with it, it boosts our 5 KW shoreside winter supply.
Its made in China as a copy of a Russian heater but basically they're the same as Webasto or Eberspacher except for the price.
I paid 220 Euro's plus 60 for customs and found it on a site called www.Wish.com
along with some stainless steel hatch handles and stainless press studs for our winter window covers.
I've got no commercial ties with them, I'm just a tight fisted bargain seeker.
BUT buyer beware, some goods look good in the photo's but are actually smaller, beware any cutting tools, they are only good for 5/6 uses, then bin them.