That should work so very close to the border.
I connected this hard drive to my MacBook Pro 2018 and connected a current meter
OEM USB voltmeter with OLED display blue transparent (voltmeter) (currently no longer available at digitec, but similar...) in between and observed it for a while.
Idle state approx. 150 to 200 mA
Read/write approx. 400 to 480 mA
In single measurements up to 510 mA!
A USB 2 connection should be able to supply 500 mA.
But the old MacBooks have more than one USB port. So to be sure, I would use a USB Y-cable. Then 1000 mA are available for the drive and there are certainly no dropouts at peak loads at the 500 mA limit.
For example a
Delock USB Y-cable (A - A, 0.30m, 3.0)
But there's something else!
You write that you want to replace your MacBook. As of OSX CATALINA, external boot disks are only supported with APFS formatting. APFS on hard disks is up to 20x slower!!! Tried it, is so, and here is an article about it.
https://bombich.com/blog...
So for MACs in future only use SSDs as external USB storage!
Good luck!
