Steve and Jeff -
Thank you both for your input. The way I did the work is by creating an Amazon S3 storage in AWS and created an Amazon EC2 (same way the link recommended), but I used Powershell to first write the .bak file to S3 bucket then upload it to the EC2 instance. I used Write-S3Object and Copy-S3Object commands to do the work. I did similar testing to copy .bak file to Azure, I first created a blob and used AzCopy PS command to upload/download the file. Both file uploads were successful.
I recommend using this method for DR, since the cost you pay is only for reserving a storage area.