This is a pretty smart idea and worth a look now that we are headed into the cold season. The Cordless Mr. Heater MH35CLP ($159, Amazon) may be a consideration if you are going to be working away from a readily available electric power supply. This new unit has the ability to store enough runtime juice in its onboard batteries for 8 hours of cordless use.
It can also be plugged into any 110v outlet and use while the batteries recharges. The force air fan allows the heater to produce a very respectable 35,000 BTU or enough to heat 800 sq ft. The new more efficient unit is also 50% quieter than other forced air units and cool enough to touch, so even if the plan is to mostly have it plugged in there are still several advantages.
We have not tested this unit out so can not testify to all it is promising but it would be nice to have an alternative to the non-electric radiant heat propane units which are not very effective at heating an entire space. For non-propane fully electric heaters up to 150,000 BTU, Ohio Power Tool supplies a wide range of options.