Great info in this thread.
I have a 6kw propane generator that is stored in the basement and on a battery maintainer. When a power failure occurs I wheel it out the back door onto the covered concrete deck. From there I have created a wall pass thru to snake my cables through. I need 220 for the well pump and use the 110 for all the other needed devices. I power the freezer, refrigerator and boiler (1 zone 1400 sq ft with indirect DHW). I have measured all of these and the generator will easily handle it.
The stove and fireplace are propane. The fireplace fan is hooked to a charger inverter that will run 8 hours.
I keep 3 propane 20lb bottles on hand. During the longest and first use of the generator I clocked 9.5 hours on 1 propane bottle.
In the almost 3 years we have been in this house we have used the generator 3 times, storm Irene was 40 hours with no power. I do not run it all the time. On for 2 hours then off for 3 or 4. When the storm is over any noted issues are logged in the generator document I use to track storms and usage.