I have been to 46 states and once I'm vaccinated I want to make that 47. After initially researching Alaska and finding out that even after the stimulus I can't afford to go there, I am now researching Hawaii.
Any advice? Is it too ambitious to want to do Oahu, Maui, AND the Big Island in just 12 days?
I'd say 12 days is the bare minimum to cram all that in. PWC and I both lived there for a number of years. I was last there in June of 2019. I'm sure we'd both be happy address any questions you may have thru a PM regarding your specific interests.
Not sure I'd choose Hawai'i as a spot to go during Covid, but only you can judge your comfort level with those limitations. Be sure to follow their Covid-19 testing protocol even if you have been fully vaccinated, and bring all of that paperwork.
The Big Island: Easily the last island I would choose to visit. It's
very large and primarily lava rock and cattle ranches other than the seaports. I never did witness the volcano eruptions, so that may be of interest to you. If you go during hurricane/tsunami season, this island will likely be at the tip of the spear...
Maui: You need to select somewhere to stay - West Maui or the Kihei area are the 2 most popular. Time Share rentals are abundant, and depending upon the time of year, can be a real bargain. I believe that either The City and County of Honolulu or The State has limited the number of Time Share rentals, so I don't know what impact that may have. If the latter, it could impact Maui inventory.
Lahaina Town will be the primary tourist destination in West Maui and the bulk of the hotels are up the road in Kaanapali. A drive to Kapalua along the Lower Honoapiilani Hwy. if you've time for that. I worked on Maui for years...never stayed in Kihei, it was always too hot. You will already have missed the prime whale watching season, though it theoretically runs thru May.
A drive to the top of Haleakala to see the sunrise is high on the to-do list. This is where NASA did the testing of the Lunar Rover. Lots of interesting foliage along the way. Not sure if this is the year for Silver Swords or not.
A drive to Hana and the Seven Pools is another must, though this is an all day adventure and there really isn't much to see when you arrive. This is more about the journey than the destination. We've a friend that lives in Hana...it's a pretty sleepy place other than for the rental car traffic.
You may want to look into a helicopter tour if you are into that. Keep in mind, this is nowhere near as crowded as Honolulu during non-Covid-19 times, but it is very popular.
Kauai: They say Maui no ka oi...but to me, Kauai is the best. Very sleepy and landscape ranging from essentially desert out towards Barking Sands, to a lush tropical climate inland, with magnificent almost deserted beaches and towering mountains and waterfalls.
Most people tend to stay in the Princeville area these days. We used to enjoy the Coco Palms Hotel back in the day (their cabins had a zoo and private swimming pools in an enclosed lanai) but it was wiped out during a hurricane and is set for demolition after having remained vacant for many, many years.
This is another place to consider a helicopter tour, perhaps even moreso than Maui, to view the Na Pali Coast and it's waterfalls. Stop at Tahiti Nui, a restaurant/bar in Hanalei on the way to Tunnels Beach. My daughter tells us there is also a restaurant across the street from Tahiti Nui that is run by a VT or UVA grad...I forget which...adorned with appropriate sports memorabilia.
Kauai just underwent significant flooding and a road closure, but I suspect things will be sorted out by the time you would get there.
Ni'ihau: While a private island, for the past 30+ years they have allowed tourists to drop in by helicopter for a very structured look at a society that has remained virtually unchanged since...essentially forever. There are no overnight accommodations.
O'ahu: I would encourage you to look into the Turtle Bay Resort in Kahuku. I think bluestreak will back me up on that. It is not far from the attractions you might want to see, but well away from the concrete jungle that is Honolulu. Do avoid rush hour...not sure how busy things are with Covid, but normally, it makes DC rush hour traffic look tame. You will pass thru more rural areas that are themselves quite popular, such as the Banzai Pipeline, Haleiwa and the Kole Kole Pass on your way to Honolulu.
The Polynesian Cultural Center in Laie is quite worthwhile, if only for the luau and evening show. You might get into the day tour...I never did, but I lived there.
From what I think I know about you, Pearl Harbor and the Pacific Aviation Museum are right in your wheelhouse.
Of course, you'll still want to see Waikiki just to cross that off your bucket list. Back in '05 our oldest daughter said to me "So this is Waikiki Beach? Lotta hype, huh?" She nailed it.
Other Thoughts I skipped Lanai and Moloka'i, as should you...
Nothing in Hawaii is cheap...not even the shave ice anymore, so be prepared to drop a pretty penny.
I'm certain I've left some things out...like Leonard's Bakery...and screwed some things up, but PWC can likely fill in some blanks...