What is current Ubiq DAG file size and how it what are the predictions about the increase of it?
DAG size increases every 30k blocks (an epoch) as defined by the Ethash protocol. Since Ubiq has an 88 second block time, the DAG size increases much slower compared to ETH or ETC.
Here is a chart from OP.
So DAG size is approx 1.15 GB or so at this stage of the network.