Are the Weatherproofing Improvements Worth it?

I live in a part of the country that gets cold, for a number of months, where the temperature can dip into the single digits F and stay there for days. I also live in a small not well insulated house with electric baseboard heat. Probably the house started out as a summer vacation cottage and morphed into a year round residence. Each baseboard unit has an on off switch, so I pretty much keep the heat off in each room unless it is needed (off in the bedroom and bathroom during the day, etc). That helps, at least the heat can be turned on and off as needed.

I keep the heat at 50-55F at night and no more than 65F when I am home. It's a bit chilly, but I wear sweatshirts and fleeces and have an extra blanket on the bed. I do have one section of the house that I keep the animals in. It started out as the front porch to the cottage and developed into a storage room. It does not have an exterior door, but it does have a number of windows (uninsulated) and it drafty. The winter north wind does like to come through the cracks.

This year as I did in previous years, I bought some plastic film to go over the windows. I usually bought the interior film and would do the 4 windows that seemed to get the most breeze. You can see and hear the wind come through that part of the house. The plastic would move as the wind blew. This year I bought the exterior window plastic, applied it as directed (temps over 25, clean dry siding, etc) and it lasted for about two weeks, then fell off. Of course, we are starting to hit a spell of cold and windy weather and the ambient temperature is below the manufacturers installation range. I was kind of annoyed to have my work fall apart so soon. It's too cold to redo the exterior window, so I think what I will do is put the exterior film up inside and see if that stays.

A couple years ago I bought this insulation that you can put behind your wall outlets to prevent heat loss and I put some insulation on my pipes. The house does need new windows, I had one window in the kitchen replaced with a very basic insulated one and it really cut down on the draftiness.

What I would really like to do is to replace the insulation in my crawl space. Half of it is on the correct way, half of it on the wrong way. (The people I bought the house from were horrible at all the supposed home improvements they did and that was one of them.) Buying the insulation is not the hard part, getting someone to go into the crawl space, take out the old and install the new stuff is the difficult part.

The other thing I would like to do is replace my gas fire. I have an old propane gas fire that I use as auxiliary heat. I only keep it on when I'm home. It has three temperatures, off, lo and high and no thermostat. It would work best in a garage or workshop, not having a thermostat means it cranks out heat. The house can go from 55 to 75 if I have the gas fire on and then drop back to 55 in a very short period of time when I turn it off. I kinda wonder if I'm wasting a lot of propane turning it on and off like that. I tend to use it in the middle of winter when it's really cold outside and I want instant warmth. It does give off heat and I find the hissing noise of the fire soothing. The animals tend to want to sleep in front of it and fry their brains. I found similar units that have thermostats, but they cost between $160-$185 (depending on the model) and then I would have to have my gas company install it ($75 just to show up to do it). It's a fairly simple connection, kinda like screwing in a new propane tank line for your gas grill, but I'm not that adventurous and would rather have a professional do the work. I'm wondering with the spike in oil prices (and thus the spike in my gas price) would it be worth the investment to have an updated unit? Or do I just wear an extra fleece, drink more tea and gut it out until next year?