miniDV tapes to ext. hd

So I have 800 GB of miniDV tapes to import into iMovie so I can store on ext. hd. I have an iMac 27" 1 TB hd that is 2/3 full and can't import all the tapes before moving to 4TB LaCie T2 d2. How can I move them? In pieces of 5 tapes at a time or is there a way to import directly to LaCie? If in pieces, will they iMovie library be actually multiple libraries?