Jan Hedlund wrote:
It may be easier and more cost-effective to look for an older Mac with a FireWire/IEEE1394 port, and then handle the transferred data on that computer.
Yes. Old Macs with built-in Firewire should be quite cheap or maybe even free as many people just trash them.
Then get old iMovie 1.0.2-6.0.3 from eBay -- I'd recommend v6.0.3.
iLife 06 (includes iMovie HD 6.0) installer doesn't run on OS X 10.7 or later because it is a PowerPC application. But iMovie HD 6.0 can be installed via Pacifist and then updated to v6.0.3 which runs in up to macOS 10.14 Mojave. But an older macOS like 10.11.6 El Capitan might be better for miniDV/D8 import.
Or just let some known-good service do the import for you. I'd ask for .dv file although a properly deinterlaced and rectangular-to-square pixel scaled .mp4 might be good unless you want to dive in to those details yourself.
All old iMovie versions have some bugs and gotchas that need workarounds so ask more, if needed.