I'm modestly familiar with Coer d Alene Idaho and Houston TX
Getting very familiar with the Raleigh area.
(I've lived in many other areas of Texas and spent a considerable amount of time in WA state).
I'm sure you've already looked up the numbers but the tax hit would be like this:
Highest to Lowest-
CA
IA
ID
NC
TX
Houston probably has the most humid summer weather and someone coming from Southern California may not be ready for that level of humidity unless you live right along the coast in San Diego...often the daytime high and the nighttime low in the summer may be only 10 degrees different such as 95 during the day and 85 at night.
Idaho will be a shock for you (very, very frigid for a Southern CA native, lots of snow - I think they've already had a snowfall or two by now, and while in Idaho they may think they have a decent amount of sun, it will feel somewhat cloudy and grey during the entire winter and part of early spring to someone from Southern California unless, once again, you lived on the coast and dealt with the Marine Layer taking your sun away).
North Carolina summers in Raleigh will also be abominably humid for anyone who is used to the very dry areas of Southern Cali, and you have never experienced bugs like they have in NC. I think I encountered fewer bugs in the rainforests of Central America as compared to what I run into daily in the Raleigh area.
I don't think you'll save too much on housing costs going to Austin. Last time I checked it was a medium-high cost of living. In Houston, you can find many areas at many price points.
I know nothing about Iowa.
I do know that the produce tends to be much fresher and more affordable in Southern California than the few places I've lived on the East Coast (NC, VA, DC, GA).
Having said all those negative things about the SouthEast - I really like living in the Raleigh area. The housing is lower medium cost...but competition for the reasonably priced homes has been fierce (sub $400K goes fast...we bought a sub $300K home in Cary that is 3bdrm/2.5bath as a fixer upper, everything in decent condition at this price point was being snatched up. On the other hand, there are plenty of homes for less than $300K in Garner, Fuquay and North Raleigh and these tend to be around 2000sq ft 3 or 4 bdrm). The trails, forests, and animal life population is amazing and may surprise you if you are from any of the more desert regions of Southern CA like LA to Riverside area).
Here is our cost of living in Cary NC:
https://forum.mrmoneymustache.com/welcome-to-the-forum/those-of-you-with-$200k-income-whats-your-typical-monthly-spending-like/msg2126633/#msg2126633Add 5.49% (flat) income tax
Property Taxes are roughly 0.8% of the home value yearly
There are many great outdoor activities nearby (bond park has a little lake/reservoir where you can rent mini sailboats or bring your kayak and many miles of trails; lake crabtree is also a nice place for fishing or boating...and if you want to use a powerboat or have a really big lake for kayaking you go to Jordan lake about a 45 minute drive to the West of Cary). Many of the bike paths connect through the city, the downtown area is still mid-revitalization but they have some cute shops there and two performing arts theaters (The Cary and Cary Arts Center). In 2019 a new library will open effectively doubling the size of the prior library and around the library/downtown park area they have concerts of various different genres of music I believe twice a week throughout the summer. A few other nearby shopping and mall areas also have summer performances every week.