Would there be more than just one Room 101 in the Ministry of Love? It seems entirely possible given that the building itself is said to be very large. I just think it wouldn't make much sense if they only had one room to tend to potentially thousands of people.
Within the text of 1984 we see repeated references to subjects being either threatened with or physically taken to "Room 101" in the Ministry of Love. Tellingly, when Winston finally ends up there we don't actually see a room number on the door despite the the detail to which Orwell goes in describing the room.
"It was bigger than most of the cells he had been in. But he hardly noticed his surroundings. All he noticed was that there were two small tables straight in front of him, each covered with green baize. One was only a metre or two from him, the other was further away, near the door. He was strapped upright in a chair, so tightly that he could move nothing, not even his head. A sort of pad gripped his head from behind, forcing him to look straight in front of him."
For a moment he was alone, then the door opened and O'Brien came in.
Although it's a well known story that Orwell was inspired to name the room after his own room at the BBC (where he was forced to sit through interminable meetings) there's no in-universe confirmation that the room in 1984 was a single room, rather than a multi-use dungeon area. The absence of a numbered door in the text strongly suggests that Room 101 isn't actually a specific room within the building but rather just a code for "torture him/her".
We can make an estimate how many Room 101s would be needed.
It is stated that 85% of the population of Oceania are proles. The ministry of love doesn't care much about indoctrinating proles, because they aren't educated enough to be a threat. That means it would be pretty rare that a prole would anger them enough to be considered important enough to drag to room 101.
That leaves 15% of the population (inner- and outer party) as potential victims. Real-world London has a little over 8 million citizens. When we assume that London in the 1984 universe has about the same number of inhabitants, that leaves us with 1.2 million party members to keep in line.
The threshold of being considered enough of a thought-criminal to be sent to room 101 doesn't seem to be very high. When Winston is put into a ministries holding cell in Part III Chapter 1, many of the prisoners who share the cell are sent to room 101, including people like Ampleforth who appear to be loyal to the regime and not much of a danger.
When we assume that 1% of all London party members experience room 101 once in their life (120.000) and a party member reaches an age of 60 (medical conditions and thus life expectancy are bad in Oceania), Room 101 needs to process 2.000 victims yearly or 5.5 victims daily. That means about 4 hours to break each person.
When everyone breaks as fast as Winston, that would be enough. But keep in mind that the tortures people experience in Room 101 is always heavily personalized. Many will require intense work and modification to Room 101 to prepare their personal nightmare. Also, the Room101 Winston visited would not be suitable for every scenario. It would, for example, be much too small to torture people who suffer from acrophobia (fear of heights) which is a very common phobia.
I would assume that the miniluv has several Room101s. Some permanently equipped for specific common phobias and some multi-purpose rooms which can be customized for people with uncommon phobias.