Chief organiser Dave Beeche said race officials were surprised to get 6000 entries this year - their year-five target - after initially expecting about 1200.
Entries for next year's event would open in two to three weeks, and he expected demand to rise significantly.
A decision on where to cap numbers would be made after a debriefing in the next week, he said.
''The vision, ultimately, is to get us to 10,000-plus, but we haven't yet quite formed a view on whether we step it straight to that, or gradually increase it.
''My gut feeling is probably the latter, but we'll see after the debrief.''
The event's long-term capacity could be determined by outside factors, such as accommodation and flights, rather than its own logistical constraints, he said.
A major beneficiary of the event was the Queenstown Trails Trust, on whose trails 70% of the marathon course was run.
As the event's official charity, it received $10 from every entrant, translating to $28,000. Trust CEO Mandy Kennedy said the funds would go towards trail maintenance and development of new trails in the Wakatipu Basin.
Mr Beeche said a ''weather bomb'' had provided a stern test of the organisers' ability to keep late-finishing runners safe and well.
St John Queenstown station manager Craig Downing said 37 people were treated at the finish line for cold weather exposure, and a male competitor was taken to Lakes District Hospital for monitoring of a minor cardiac-related condition.
Most of those treated were late finishers caught in the ''cold snap'' from about 2pm, Mr Downing said. They were taken to a specially prepared room where they were monitored and gradually warmed up.
St John had 27 staff and three ambulances working at the event, including paramedics from Dunedin.
A planned prizegiving ceremony was cancelled because of the weather.