It's almost impossible to put even 1 person with his or her 2 or more big luggages into any apartment unless you own a big house. The space is really limited and it will bring huge inconvenience for everybody. For example, most family, without their own house, don't have extra bed or sleepbag and such accessories. And I doubt if people can walk in the apartment after everything arrives.
If the landing date is between May and August, I suggest you ask your friend to reserve a room at any residence of nearby university and the weekly cost is between 100- 200$.
But if it's from September to April, you can get a room at Comfort INN or similar hotel for around 50$/day and at that time it's much easier to find
an apartment than summer.
Therefore they will have enough time to find
a suitable apartment for themselves with my help.