Although Charles has not been very specific during his latest update, the intention is probably to let the current ITN continue all the way to Shelley Mainnet.
However, a lot will depend on when the ITN treasury will run empty.
As of April 11, there were 79.9M tADA left, with 356M tADA in rewards paid out so far during 119 epochs.
With approx. 3M tADA left in the ITN treasury, rewards theoretically can no longer be paid out after epoch 145, which is around May 7.
Unless additional funds are found elsewhere. So, let's see...