Method of uploading contacts to a new iPhone? iPhone version: Up-to-Date (iOS - 10)

I have more than 10,000 contacts in my phone.

I recently tried to transfer them to a new [i]phone but with no luck...
The backup is sitting in my email as a .vcf file.

My method of uploading the contacts to the phone is:
Mail App-> "Backup June 27"->Download the File-> To contacts -> Crashes at this point.

I don't have a save on iCloud.

So, I was wondering: what are all the ways (which might include Windows or Mac and so they are included) to upload a backup to an iPhone?
Looking around, it appears there may be an app called Contacts Kit on the Mac app store. If I read correctly, this can be used to export the contacts to a file (which I know you have already done, however your file may be corrupted considering the process crashes) and then you do the steps in mail you did previously.

One thing I may suggest is that you open the App Switcher by double pressing the home button, and swiping upwards on every app but the mail app to close them off and free up memory. Considering your contacts list is in the hundreds of thousands you may simply be running out of memory, as I've had apps crash before when I ran out of memory. This can especially happen if the phone is older (thinking iPhone 5 as it can have as little as 512mb of RAM, yet still run iOS 10).