Double checked on the wiki its a one time event. Kinda sucks but most of the fox den content requires you to now what you can and cannot skip. So yea unless you have a save before that you are screwed on that note. I recommend saving in another file every 5-10 days and then when your sure you dont need them anymore to compress them to 10-20 day intervals so in case you later notice you messed up you can fall back and only have to replay 10-20days of progress.