Let us know how you get on. My feeling is that it won't work, but I really would love to be proved wrong, as there's plenty of older cameras out there with IEEE1398 and no way of getting the material off in high quality if you have a modern PC.
I have a Dell XPS15 with a Thunderbolt 3 port, and can confirm that plugging an Apple Thunderbolt 3 to Thunderbolt 2 adapter into the machine, then a Thunderbolt 2 to Firewire adapter into that does (surprisingly) work.