I would think a heater would be a wise accessory…
When I was planning my great outdoor layout (before the downsizing and the move to the great indoors), I used to think that an ‘outhouse’ type building would be good idea that would act as a dispatchers control shed, It would act as housing for the powerpack, switch controls, and all the wiring harnesses, ( I was still thinking “big HO laoyout” at the time) It would also be where all the ‘paperwork’ would be given out or turned back in, but the popularity of R/C, and DCC has simplified the track wiring issues to the point with R/C that there is none, maybe switch wiring at most. The idea of walkaround control, hand throwing switches, headset communication, etc, has all but eliminated the need for any sort of centralized dispatchers control shed on even the largest layouts.
Freds idea of a grandios refrigerator container sounds interesting though…