I had an EtG test today with a cutoff of 500ng/ml and my EtG level came back at around 1000ng/ml.My question is that my sample is now frozen and waiting to be sent off does the level of EtG stay the same or does it come down when thawing? Do I have a chance of it being at 500 or below if I send it off?

No.

Why would they do anything that would degrade a sample?