I keep a portable AC (or 2) in storage at my places and whip them out during emergencies for guests. 

I would buy and keep in reserve one of the portable units on wheels...

The portable heaters are a good idea , UNTIL you get the furnace repaired .

-Sauna-Hot Tub-Patio/courtyard (large cement tiles on crushed bluestone with lighting, natural gas line to bbq)-Secondary patio off primary suite-Losing sq feet in the primary bedroom to enlarge the bathroom-High grade cabinets-Appliances with cabinet fronts-High end appliances (Viking/Miele instead of GE Cafe)-Outdoor shower (teak box walls with a dry well beneath the footprint)-Wiring for Cat6 to every room-Wiring for surround speakers (or including the speakers that are built into the walls)-Sonos whole-home audio system-Hardwired cameras (with on-site storage) to the exterior of the house-Smart features: thermostats are a given, but how about light fixtures, switches, aromatherapy, fans ... anything else?

He said the issues they found were (1) we had a portable heater instead of a built in heater (easily corrected) and (2) the neighborhood is zoned mixed use (meaning a studio behind the main house is "probably" OK) but if we want to do it we have to get our individual property "permitted" for multifamily by the city.

The ones that come with the unit are small and light weight to allow for portability of the trailer on the road.

I've never done this but I've heard that the portable shipping containers dont need much as far as rezoning because they are not fixed in place...they are more like sheds.

Sean, In our experience the best practice some of our clients use is to purchase portable fans and leave them in the unit until the issue is resolved.  

Under the old VA Foreclosure system where you had your key and bid online I ran across a fellow investor who had a portable generator in his pickup.

I was able to go into the title company a few times and sign in July  but this week I had 4 sets of construction loans and we did it in my driveway on the title companies customer service reps portable table.. mask gloves fresh pen that gets thrown away etc.