FEMA is ill-suited to this mission, due to its need to place bids for relief supplies and then make contracts for delivery.
The US Army is much better suited for this. They have people trained in how to deliver supplies through rough terrain, in any weather, and adverse security conditions.
They have mobile water purification units
They have mobile field kitchens
They have fuel trucks that will go anywhere.
They have warehouses full of MREs.
And the military's supply and logistics units are mostly National Guard and Reserves, and much of the stuff is distributed all over the country.
A competent solution would have involved mobilizing Army and National Guard support units, which could have used their ready supplies, stores, and equipment immediately, and then replaced used-up stuff at leisure.