After months of speculation, the 36-year-old Spaniard will announce a decision over the coming weeks about his racing plans for 2018.
The question has centered on whether he will stay with McLaren or move to another team, but Alonso concedes that his fate may lie outside the sport if he cannot contend for race wins and championships.
"Formula One is still my priority, it's my life, and winning the world championship is what I'm hoping," Alonso told CNN's The Circuit.
"If I don't see any project that will allow me to fight for the win I will look outside F1 -- but that's (a decision I will make around) November-December. I will try all the possibilities before that."
Despite advancing years -- he turned 36 in July -- and being saddled with an uncompetitive McLaren car for the past three seasons, Alonso's hunger for success remains undimmed -- fueled in part by the new, faster 2017 F1 cars, and his one-off appearance at the Indianapolis 500 in May.
"I went to Indianapolis and I had that feeling again that I can win this race ... the feeling that you could win that race was special," Alonso said.
Given he had zero experience on oval tracks prior to entering the Indy 500, some drivers openly feared for Alonso's safety
-- Scott Dixon's horrific crash
during the 2017 race graphically illustrated just how dangerous IndyCar can be.
But Alonso, ever the racer, was focused on the victory.
"When I jump in the car, I put my legs inside the cockpit, the mechanics put the belts on, (and I'm thinking) when I take the belts off and I pull myself out of the car maybe I am the winner of this race -- I was thinking that in this moment. That feeling was magic."
It wasn't to be -- his race unraveled in all too familiar fashion with an engine blow out 21 laps from home, spoiling what was widely hailed as an hugely impressive IndyCar debut.
The crowds reaction not just to Alonso but all the drivers taking part also made a huge impact on the F1 star.
"I think it's a different culture, a different way of understanding motorsport or sport in general -- much more open, much more friendly to all of us," he said.
"It's the kind of feeling that the sport is beyond nationalities. All of us there were heroes for all the people in the grandstand. They support all of us in the same way and they really enjoyed the race."
In terms of "places Alonso would rather be," IndyCar, he insists, isn't one of them right now -- although he doesn't rule out another stateside adventure.
"My first priority is F1 -- winning the third world championship, but I want to attempt the triple crown as well," he said, referring to the bid to win the Monaco Grand Prix (which he has won twice) the Indy 500 and Le Mans 24-hour race.
"It may happen," he said. "I would like to go back there but maybe not in the very near future."