Comment dire "to end up" in the Writing Exercise "Recalling a Snowy Evening

Question

In the writing exercise "Recalling a Snowy Evening" you gave the sentence.  
"The next day, we ended up building the biggest snowman in the village" and gave a tip to use the plus-que-parfait.
I used the verb "se retrouver" for "end up" which I had learned in another writing exercise: 
Le lendemain, nous nous étions retrouvés à construire le plus grand bonhomme de neige du village.
The correct response was: Le lendemain, on avait fini par construire le plus grand bonhomme de neige du village. 
I thought "on avait fini par" meant "we had finished by" and "On s'était retrouvé" meant "We had ended up by"
Can you please clarify why the use of se retrouver was wrong?
Or if it was right, could you add it to the exercise as an alternative response?
Je vous remercie d'avance de votre réponse!

Cécile Janty-Davies · Accepted Answer

Bonjour Rhonda, 
Et félicitations pour avoir suggéré une réponse alternative à laquelle je n'aurais pas pensé moi-même!
Nous en avons parlé et l'avons ajoutée.
Bonne Continuation !

Rhonda Mattern · Answer

Thanks so much for your response! Just so you know, the reason I even used "se retrouver" to mean "we ended up" is because one of the other writing exercises used se retrouver as meaning "to end up."  That's why I thought adding this alternative to the list of possible alternative answers would be a good idea...because seeing it clearly defined as "to end up" in one writing exercise and then having to mark my response as wrong in another writing exercise was depressing and confusing!!!