Off the top of my head some of this infrastructure already exists within the Wildfire worldFeeling left out from participating in yet another thread derail...
Or maybe Emergency Preparedness Canada should store modular facilities that can be set up wherever they are required in an emergency (soccer field, farmer's field, empty lot, etc.) and not be bound to where the Armoury is located or to any other existing building which may be damaged/unusable in case of a natural disaster?
In Alberta we contract via 3rd parties for camps to be installed, within 24 hours of first call, anywhere in the province up to 250? person capacity. That's Command Post, wash cars, and kitchen/dining hall + a very limited number of private rooms. Call up Horizon North, to name one company, and as long as you are willing to meet their costs it's pretty amazing how almost any flat surface can be used. There are multiple ICP posts that can also be deployed as a single ATCO trailer sized unit that the province owns along with pre-packed warehouse set ups up to and including a field refurbishment trailer.
British Columbia uses a mix of in house camp facilities (kitchen, mess tent, some wall tents, washrooms) that they own, set up and maintain or, if short, uses 3rd party contracts to supply incidents. Outfits such as tree planting contractors are a common source of kitchens/dining/wash car set up with washrooms via porta pottie rental and other supports. Standard cargo trailers are often used as warehouses and/or local depots depending on options.
Ontario has a set of trailers that are modified standard cargo trailers converted into tiny individual bunk rooms. Pull up and it's 10? rooms per trailer plus another for washcar. There is less emphasis upon dining facilities as they tend to camp their crews on the line more than BC/AB and so it's more about delivery of groceries to crews than setting up a mess hall.
There is a lot of discussion however going on in regards to emergency response as not all hazards are as integrated as wildfire agencies are and frankly the funding/capacity varies widely. I would however rather focus upon smaller, helicopter portable materials than expensive hardwall trailers that require large trucks to access areas because those are often the resources tougher to get than a hall/building etc. Ranger tents are an excellent investment in my mind as they can be used for multiple incident types up to and including medical aid triage buildings as are items such as cots that are needed to convert facilities like hockey rinks to evacuation centers.
However as any emergency is multiple level - local emergency -> municipal emergency, -> provincial emergency -> National emergency I believe there is also an obligation for those parties below the federal government to be responsible instead of only relying up the federal gov't which is a) not well distributed nationally in terms of presence and b) will be slower than lower levels to respond. Emergency Preparedness Canada does have a role to play in helping to coordinate certification consistency and training in the same manner than FEMA in the USA has worked with the USFS/BLM/NP to ensure consistency in certification processes and needs. You can take different courses through each agency but they are all clearly spelled out that you will have FEMA course X or USFS course Y for this process and are recognized as peer equivalent.