Nobody mentioned the second idea (to my knowledge) except me. But before I personally spend a dollar to fix anything, I compare it to the cost/benefit of buying a new one, then I make my decision.
I do know Wayne was looking at adding a retractable roof, and then seemed to back off the idea. I don't know if this is because it can't physically be done, if it would be too expensive, or for some other reason... but I was disappointed to hear that news. Everyone knows how much money can be made from being able to hold huge conventions... for example, that's why Atlantic City lost the Miss America Pageant. A.C. couldn't compete against what other larger cities with better climates could offer.
I don't think the Dolphins are moving, but I do get nervous when I see so many orange empty seats on TV. (I don't live in FL.) If it was a more comfortable place to see a game on their worst weather days (heat advisories & monsoons), maybe it would sell out, maybe not. It would take a focus group or two to be positive.
IMO, you will not see stadiums reach the age of the Orange Bowl anymore. It's just cheaper in the long run to build a new stadium with everything you want in it rather than getting nickel and dimed to death upgrading every ten years. Some things can't be upgraded after the fact regardless of how much money you throw at it--perhaps a retractable roof is the perfect example of that.
I doubt Dolphin Stadium will ever celebrate it's 40th anniversary, because it won't be able to compete with state of the art stadiums in 2027 regardless of the current facelift project or any that come along after it.