The ITC issued a document on THE HOPE OF SALVATION FOR INFANTS 
WHO DIE WITHOUT BEING BAPTISED. 

It goes into these questions in paragraph 94. Overall it maintains that there are many theological opinions on this issue, but it concludes:

"Rather, as we want to reaffirm in conclusion, [our considerations] provide strong grounds for hope that God will save infants when we have not been able to do for them what we would have wished to do, namely, to baptize them into the faith and life of the Church."