The five-year-old stormed through the gruelling conditions in Paris to give the hugely-popular trainer the proudest moment of his career in the Prix de l'Arc de Triomphe.
With a second career as a broodmare awaiting next year at her owner Kirsten Rausing's Lanwades Stud, a trip to Japan has emerged as the only real possible swansong for Alpinista.
On top of the £2.6million for winning in Japan, there is also a £2.7million bonus on offer for winning the Arc and Japan Cup.
"There might be another run this season, but she'll be retired at the end of this season," Prescott told talkSPORT2.
"Ms Rausing is a breeder through and through and she can't wait to see her in the paddock outside the house and you can imagine that, you've created your dream so you want to see it.
"She's in the Japan Cup and that is still the possibility. I'd be tempted to go. Because she's won the Arc, if she won she'd get an extra £3m so it's a £6m purse if she won.
"So it would be tempting but the contrary argument is who wants to see her beat now? Of course, for the poor trainer the thought of 10 per cent of £6m is nice, but I can see the contrary argument."
Alpinista appeared among 10 British and Irish nominations for the race on November 27.
King George winner Pyledriver, Melbourne Cup favourite Deauville Legend and the William Haggas-trained pair of Sea La Rosa and Lilac Road could also make the trip.