Keeping humans alive on Mars would require nuclear power sources much larger then any that have been flung into space so far.
If you are thinking of solar power then consider than the watts per square meter is about 40% of that on earth, that a big pile of batteries would be needed as well and how much work it would be to maintain a huge solar farm.
Mars is cold, but I don't think that's a huge problem. You just need an appropriate amount of insulation.
I imagine a typical Mars habitat to be either sealed section of an existing lava tube or some kind of dome structure built at the bottom of a hole and then covered with sand, except for a stairwell. Either way, you'd line the inside with something. Aerogel, polystyrene, whatever works in that environment and whose ingredients can be transported to Mars in a compact form.
And then of course you need to also survive 14 days of no sunlight at all. At least here vacuum helps to reduce heat loss. :)