Weird the stuff people argue about.
An electric radiant heater may be '100% efficient' but only when it's on and burning watts. The oil in those heaters retains and distributes heat between power on cycles. On for five minutes, off for ten uses less watts than on for fifteen minutes. Many of them are 1,000 or 1,500 watts instead of higher wattage 'glowing' red hot' radiant units.
On canning and freezing. Considering the months of growing and all the costs of seed, fertilizers, insect and disease control, the labor involved in all of that plus the harvesting, then the labor and energy used in preparing, canning or freezing, not to mention the supplies needed for those, are you really saving anything? Has anyone really counted the beans for all of that? And then, is the resulting food really all that much better? Fresh is, I won't argue that, but this is about the stored stuff six months later. Heating a kitchen for days at a time (between cooking what needs to be cooked and heating the canning jars) isn't free. Standing over a hot stove or sink isn't fun.
It's the same with wood for heat. It ain't 'free'. It may or may not cost less overall than utilities, and it's nice to have heat when there is an outage of some kind, but it's an incredible lot of work. I've only done it for less than 10 years and I'm about done with it. I have no wood stored for this winter, opting for gas this time around. I have a few small sections of log I could cut and split in an emergency. I changed home owner's insurance and this company doesn't cover 'solid fuel' sources which saved me a few hundred dollars. At least they didn't require removal of the stove and vent pipes (yet), so I could use it at my own risk.
It's all about individual choices and what works for one, won't for another. There is no one right way to any of these methods.