As he handed back his studio earpiece following his final news bulletin after a 14-year-stint at the helm, Cantwell admitted that he felt "kind of sad but excited" leaving the station.
The 44-year-old newsman said the move from TV3 marks the culmination of a new year's resolution he made to himself this time last year – that he would spread his wings and would not still be at TV3 in 12 months' time.
"It's no secret – I decided that after 14 years, I felt I had achieved everything I had set out to do at TV3. I'm turning 45 in June so I felt that I could stay here for another 10 or 15 years, or I could set out and try to fulfil my potential," he said.
"I have two daughters who are still young enough if we had to move away and my wife is very supportive of me. You only get one bite at the cherry," he continued.
He said 14 years was a long time to spend with any organisation, but was keeping his cards close to his chest on his future plans.
The former INN news editor said he would consider a move back to radio, which remains his true love due to its intimate nature.
And he admitted the States would be good because he already spends as much time as he can over there, visiting at least once a year, and enjoys the place and the people.
He said he hadn't even thought about whether the Irish accent might be a bonus in the job – but laughed as he said that if he could use it to his advantage, he would.