Power Query Refresh from Folder

I receive daily .csv files via e-mail (unfortunately I can't access the original source). Each data file contains information for yesterday, today, and tomorrow. Therefore, the most accurate information is recorded for the earliest date for each data file.

 

I am trying to create a query or multiple queries to pull data from multiple .csv files and be able to do the following:

 

1. Pull the earliest date from EACH file and de-dup some rows based on criteria. I tried doing this, but it seems to pull the earliest date not by file, but from all the .csv files. So, if I wanted the 2 Feb from one file and 3 Feb from another, it's only pulling the "earliest" from both (2 Feb).

 

2. Refresh ONLY new .csv files I add to the folder. I need to manually go through some of the rows and delete due to issues from the data source, so when I refresh I don't want it to run through the other files. 

 

Thoughts? I was thinking maybe there's a way to create a table and append it with the new data somehow, but I get stuck in the process.

 

Thanks!