Using a temp table when using MERGE with a remote table

Hello
I use the MERGE statement for updating a Local table using a Remote table as the source, and this is made every 30 minutes. The Local table is read heavily by an application and I am worried if the described job affects overall performance.
I came up with the following idea and I would like to read your opinions: To place an addition local table, identical to the other, and making the first MERGE with this table. Then making an addition MERGE using now both local tables. What do you think?
Thanks a lot.