Can Storage Gateway handle 8 TB of local file data with the potential to grow up to 18TB?

Hi, A customer has asked the following question. I have looked on the Storage Gateway whitepaper but could see and answer relevant.

"We're looking to off-site a copy of our physical file server for DR purposes. I very recently came across the option for AWS Storage Gateway and was wondering if this would be what we're after. We have currently 8TB of local file data with the potential to grow up to 18TB.

If we used this as our off-site backup how would we mount that in the future to a device/server on AWS?