Initial Suggestions:
1.don't do it that way at all.
2. certainly don't take the advice of ANYONE on the net and run it on your prod environment without testing it if you value your career.
From my own experience - just trying to pull 50M rows over a linked server connection is going to be a BAD outcome. Hell - pulling 50M rows on the SAME server will tend to affect performance if you do it in one big batch.
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Your lack of planning does not constitute an emergency on my part...unless you're my manager...or a director and above...or a really loud-spoken end-user..All right - what was my emergency again?