I did the ground exams first and managed the PPL course in just under 14 days in Florida, but it was hard work; I hit the ground running (2 flights on the first day, 3 on the second) but that's a bit harder now that you might lose a couple of days at the start until you get your fingerprints taken.
That particular school now uses an aircraft which may take a little longer for studes to master to solo level - not helping if time is tight.
When I did it the advertising was very much "guaranteed pass in 21 days", (albeit with some small print caveats!) but I don't think the school is saying that now.
I would still recommend the intensive US training approach, but plan on 4 weeks to build in a comfort margin.