I captured hundreds of old MiniDV (also DVCAM and HDV) tapes back around 2016, still have about a hundred left to do, but kind of lost interest in the project. I used my 2012 2.6ghz quad i7 Mini at the time, it was quite a machine in its day and I paid over $1,300 for it.
But today, you can get these for a song - MacSales (aka Other World Computing) sells them used with a limited warranty, the same spec as mine only costs $200 now. You would also probably be fine with a cheaper/lower spec configuration, they have some for under $100 on their site.
For me, the big attraction of the 2012 Mini is that it has a firewire port. Also has thunderbolt 1 and USB 3.0, so there are good options for external disks to store the digitized videos. Anyway, at those prices, might be another approach to consider and it wouldn't tie up your new computer during capture.