What conclusion can be drawn about Bilbo's party based on the description of the setting?

We can conclude that t he party will be large and extravagant and will be held outdoors.

Bilbo is celebrating his 111th birthday and he wants all of Hobbiton to come to his party to celebrate with him. He also has other plans - he wants to leave the Shire for good and go on his final adventure. This is why he wants to throw a huge party - in part to celebrate, and in part to say goodbye to everyone before he secretly leaves.