As a host, your only obligation is to open up your homes to as many athletes as you are comfortable with, I try to make sure all the athletes have a bed but sometimes they are ok with a couch or something on the floor. We also would like you to allow them access to your kitchen and a safe place to store their bikes. Anything else you want to do to make their stay more comfortable is entirely up to you.
As the race gets closer and I get requests from riders to match them up with housing appropriate to their team size. There will be anything from teams of 8 down to single riders or groups of 1-2. If you have a neighbor or two who might be interested this helps with keeping large teams in the same neighborhood since they usually drive up in 1 vehicle.