SQL Server: I need to estimate execution time of a SELECT .. INTO .. statement
On SQL Server 2008 R2, SELECT...INTO queries are not eligible for parallelism (this was introduced in SQL Server 2014).  So the increased CPU count in production will not help your overall runtime unfortunately.

You could re-run your test with a pre-created BACKUP_TABLE, and then use INSERT INTO...SELECT to see how parallelism affects the test.



Regardless of parallelism, since you're copying a 220 GB table, it's likely that your main bottleneck is disk speed.  Specifically writing all of this to the transaction log.  I'd check to make sure that you aren't going to experience file growth events (pre-grow the production log file to whatever the size of the test instance ended up at).

I'd run your test again and measure wait stats to see how much you're hitting WRITELOG waits.  You can use Paul Randal's scripts for that:

Capturing wait statistics for a period of time

Run this multiple times while the insert is running, for 30, 60, or 90 second intervals for example, to get a feel for where the bottlenecks are.

You mentioned that your test was run on a system with no other concurrent activity against this table.  The other thing that might affect your test is if the SELECT INTO query gets blocked by other processes.