I had similar concerns when I was deciding on a back-up generator. We had a 4 day power outage following an ice storm and was ill prepared at the time. Luckily, I was coming home from work at the time and was able to purchase a portable generator and hook it up to power necessary loads. After this episode, I started looking into options.
Due to my long commute and the real possibility of not being able to come home from work in the event of another power outage, I opted for a "Whole House" stand-by generator with Auto transfer switch for my solution. At the time, I even considered making hook-ups for the portable generator in the event the stand-by generator failed. Here's the way I looked at it. We live in central Illinois so winters are cold. To me, hot weather is less of an issue and though it might be uncomfortable, in most cases it wouldn't be life threatening. Extreme cold on the other hand can be. Add to that the real potential for frozen and broken water lines as a result made my choice for me.
Even though I am now retired and we are planning on building a new house, I will be installing a stand-by power supply. My desire would be using grid tied power inverters with a battery bank for emergency loads like heat and lights. I would have a generator with this set-up to power loads that the battery bank and inverters wouldn't be able to handle and for recharging the battery bank when needed. Ideally, the generator would be hooked up in a standby style that could be started automatically by a low battery condition or manually when larger loads are needed. I've researched open source electronics like Arduino, TI Lauchpad MSP, and/or Raspberry Pi for this purpose to greatly lower the price as well as the ability to easily customize it for my use/purpose.
At a minimum, I will have another stand-by generator with auto transfer switch capable of powering all my loads. I know cost is an issue, but having a generator that performs an automatic weekly test run as well as starts and auto transfers to power the house is worth it to me. I don't have to go out in the dark in nasty weather to connect up a generator and try to get it started. It also monitors for grid power return, auto transfers back, does a cool down cycle of the generator engine, and shuts itself off to a stand-by state.
My current one runs off of propane as I live in the country where natural gas isn't an option. My furnace and hot water heater are also propane. I opted for the 1,000 gallon propane tank which gives me ample supply of fuel in the event of a long outage. I also never let it get much below 50% full in the winter months for this reason.
I still wish I'd pre-installed all the wiring and connections in order to hook up the portable generator in the event the stand-by fails for any reason. This would make thinks much easier and safer should I not be around or able to perform this, if needed.
