Adam Clarke on Titus 3:12

When I shall send Artemas - or Tychicus - These were either deacons or presbyters, which the apostle intended to send to Crete, to supply the place of Titus. Who Artemas was we know not; he is not mentioned in any other place in the New Testament. Tychicus was a native of Asia, as we learn from Act 20:4 (note).

Be diligent to come unto me to Nicopolis - Nicopolis was a city of Epirus, on the gulf of Ambracia, near to Actium, which Augustus built in commemoration of his victory over Mark Antony. There was another Nicopolis in Thrace, at the entrance of Macedonia, on the river Nessus; but the former is supposed to be the place here intended.

For I have determined there to winter - Hence the apostle was at liberty, seeing his spending the winter at this or at any other practicable place depended on his own determination. It was probably now pretty late in the autumn, and the apostle was now drawing near to Nicopolis; for he certainly was not yet arrived, else he would not have said, I have determined εκει, There, to winter.