It should not take too many resources to set up for a small party, but then again there might not be enough time to cook a great meal. If a host thinks they cannot provide an excellent feast for a modest-sized group, then the solution might be a catering service. Some kitchens demand a minimum size, but a few good ones are willing to serve a party of any size.
Catering for small parties has some advantages and disadvantages. The main disadvantage is calling a kitchen to prepare and deliver a full meal to a group that is smaller than its kitchen might be designed for. This is where it is great to find caterers that are able to scale down to a small level. Their services do not have to be expensive if their business is built around modest quantities.