As for a ballroom -- in S&S, chap 36, Robert Ferrars said when his friend wanted to give a dance, he advised her --
"Lady Elliott wished to give a dance. 'But how can it be done?' said she; 'my dear Ferrars, do tell me how it is to be managed. There is not a room in this cottage that will hold ten couple, and where can the supper be?"" I immediately saw that there could be no difficulty in it, so I said, 'My dear Lady Elliott, do not be uneasy. The dining parlour will admit eighteen couple with ease; card-tables may be placed in the drawing-room; the library may be open for tea and other refreshments; and let the supper be set out in the saloon.' "
So there need not be a formal ballroom (was there really a formal ballroom at Netherfield?), and even Lady Cat pronounced the rooms at Longbourn to be decent looking rooms.
"Lady Elliott wished to give a dance. 'But how can it be done?' said she; 'my dear Ferrars, do tell me how it is to be managed. There is not a room in this cottage that will hold ten couple, and where can the supper be?"" I immediately saw that there could be no difficulty in it, so I said, 'My dear Lady Elliott, do not be uneasy. The dining parlour will admit eighteen couple with ease; card-tables may be placed in the drawing-room; the library may be open for tea and other refreshments; and let the supper be set out in the saloon.' "
So there need not be a formal ballroom (was there really a formal ballroom at Netherfield?), and even Lady Cat pronounced the rooms at Longbourn to be decent looking rooms.