Expected time to download and install redtsone build on threshold build pc

I have a surface 3 LTE version, I have the 14393 build update ready to download and install - any ideas how long it would take? So I know whether to do it now or when I have more time

Also, any idea of the size of the download so I can estimate download time? I'll be using wired net of medium speed (I think 8Mbps)

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