IMO, the #1 condition of your success moving to the DR is you, and your attitude. A truism in life: you cannot run away from yourself. You make yourself happy, not the place.
There are challenges to living in the DR are numerous. The differences depend on where your living baseline is. The seems DR is more "foreign" if you're from, say, Omaha than if you're from Washington Heights.
If your personality is averse to change, I would reconsider the move. If your personality embraces change, moving may be a new lease on life.
Another factor is where you choose to relocate. Some areas are easier than others, and some neighborhoods within that area are daunting. The Capital is different from tourist areas and campos.
It also depends on how you need to live. 24/7 electricity and air conditioning? Ha! Good luck. If you don't know basic home repairs, electric, plumbing and water management, waterproofing, electrical management, maybe basic car mechanics, you'll be frustrated. If you do, it's almost fun.
You'll need to develop a thick skin in dealing with poorer people who perceive you as rich. If you don't develop a cynicism toward many people who suddenly want to befriend you, expect more frustrations.
If you don't have productive activities, a job, hobbies or volunteer work Chronic Barstoolism may set in. Idle hands and minds can become their own worst enemies.
I like living here. It's been ten and half years. Now we live in what I consider the nicest town in the DR, a sort of vacation suburb, Jarabacoa. We enjoy small town mountain living with 45-minute access to a modern world with excellent healthcare and shopping options. It's not as expensive as many areas, but a lot nicer and secure than campos.
On a cost basis, if you try to duplicate how you currently live, the DR it can be much more expensive. If you can adapt to Dominican life and choose your compromises well, the DR can be a very reasonable place to live. Fortunately many more and less-expensive consumer options and services are becoming available. Maybe not like the First World, but a HUGE difference from ten years ago. But it still ain't Kansas.
And keep in mind: some expats are among the least trustworthy people you can deal with. Just because they speak your language, while a good basis for conversation, it does NOT mean they are good, honest people. Mant expats are trying to run away from themselves in the DR. That is a hard lesson for many expats to learn.
But bottom line: if you and your spouse aren't happy where you live now, you won't be happy in the DR. YOU make the difference, not the place.