Is 21 days in Samara too much?

Hey all! Some great information in this subreddit! I'm planning a three week trip with my wife and four kids to Costa Rica through much of August this year. We found a beautiful spot about 15 min away from Samara Beach on Airbnb with availability for that whole time. We're planning to do a two week vacation, and use the final week for sort of a remote working excursion since I can work from wherever. Is 21 days too long? Is there another spot folks would suggest we split our time between coming from Liberia? Kids are 4, 4, 9 and 11. Thanks!