Hi
Welcome to Fieldlines.
Overall, the cost of RE goes up as the reliability requirement goes up. Same for the level of automation needed.
There are some very cheap and effective RE systems out there, but usually the owner needs to be there to monitor things.
If you already have natural gas at this house/cabin, then you already have an ideal heat source to use. In my jurisdiction, a unit of energy from natural gas costs half as much as an equivalent unit of electricity from the grid, and yours may be similar. If the house/cabin also has a grid hook-up, then it already has access to the most trouble-free set-it-and-forget-it system of power distribution, probably. I'm not thrilled with paying for an ever-increasing electric bill, but the cost to convert my house doesn't justify it. The math in your jurisdiction may go the other way.
To set up a reliable automated system with RE requires a $ignificant investment. If you are keen to learn, and willing to put in some work to earn it, then putting together your own electrical supply based on wind and solar can be very rewarding and satisfying. Some folks opt to purchase grid-tie equipment, sign the contract with the utility company, and hire people to bolt solar panels to their roofs. They are doing a good thing, but in my opinion this approach does not offer the sense of personal agency and control over one's own energy production. They will be dependent upon the installers for help later, and dependent on the pay-back rate the utility is forced to pay them. Based on the way you're asking your questions, I think you're willing and able to do some of this work yourself. If so, then that effort pays off in the short run and long run, in lower installed costs and maintenance you can do yourself. The more of your own energy you can use yourself, the less you'll rely on the utility's good will.
The winter heating requirement is partly determined by whether this is a house with all the facilities, or a cabin with no running water. If you are away from a cabin that has no running water, then obviously you don't need to keep it above freezing and maybe it won't need to be heated at all. If there is running water, and it can't all be drained back down to the well, then the heat can only be turned down to about 10 degrees C above freezing before local cold spots in the house are at risk during a cold snap. The cost of natural gas needed to maintain a subsistence level of heat in an unoccupied cabin is pretty small (it would cost less than 50$/month to do that in my house, for example) which sets a practical limit on the cost/benefit of any other system you might choose.
Some buildings are easier to retro-fit to RE than others. Flat roof / east-west facing roof slopes make for challenging PV installations. Tall trees surrounding the house make PV tricky and can render wind useless. These factors will also make a big difference between and easy/obvious installation or a difficult one.
