It's possible. You only need to clear the Beginner and Intermediate stages for the 1st and 2nd half of the event, then get 1 medal each in the Advanced stages. Just don't keep wasting stamina on a map you can't clear and reinvest that to grinding secret gardens for manyus.

You can also wait for the 4 Maps in Phase 2, were the first 2 maps will also be easy for Newcomers.