OP here -- with a 112M model you should be able to get something worth playing with using 2.24B tokens. The Chinchilla heuristic is tokens = 20 x parameters. Obviously you cam get a better result by grinding through more tokens, but it will be very slow progress. It's worth noting that Andrej Karpathy is using the 20x thing for his nanochat project.

I try to explain the Chinchilla paper in the post, but your favourite AI should be able to explain it well, and has the benefit that you can ask follow-up questions.