If you are just going to Oahu, it might be worth it. But if you want to go to the other islands, you will have to transport to and from Honolulu at about $500-$900 each round trip depending on the size of your vehicle. So if you visit the Big Island and Maui, you're looking at an additional $1000-$2000 plus the $1700 and "slightly cheaper" return rate. So your trip now costs an additional $4000 or so. And that doesn't even cover a place to stay.
I know we get spoiled with our RVs, but in this case, I would save that money and rent a condo or just get a hotel room and rent a vehicle on each island as needed.
I pulled the rates from the automobiles pdf on this site:
https://htbyb.com/shipping-price-estimator/