In other words their entire temperaments would have had to change. I agree that with very adaptable, pragmatic, rather placid people, settling for that sort of marriage might have worked.
She wouldn't have been able to let sleeping dogs lie and so it would never have worked, IMHO!
I was working on the idea that if they said "lets give things another go, let's put aside our other lovers, make some changes, see a marriage guidance counslloer"
But I agree that I think ti would stil have been unlikely to work. I think that by the later 80s they had gotten angry with each other, it was hard to even be pleasant.. And If Say Cam had gone abroad, and Diana had say Given up Hewitt.. I think in the end they would have been back in the same mess again, even if they tried. (and I think they both WOULD try).
Diana was older, Diana had developed by then. She had new interests that were more and more unlike the RF's.. She was into keep fit, tennis, charities like AIDS. She had an urban lifestyle and friends In the Celeb world that she enjoyed seeing. She was trying in her way to learn about things, took her charity work more and more seriously... but she did it HER way not their way.
Charles ad the RF remained old fashioned and country oriented.
I can sort of imagine Diana watching Charles digging in the garden and telling her the Latin names of flowers and plants and her struggling to maintain a show of interest...
And I suspect that they would still iriritate each other and there would be arguments that she'd promised to go to a flower show and here she was all dressed up to go for lunch in town with Tim Nice but Dim.. and Or that he had promised to go to an Aids Ballet benefit and he was trying to get out of it and watch a play on TV...
and I think that in time they would botht have ended up confiding in a new friend who might well become a lover..
Maybe Charles would not find a woman who was as close to him as Camilla, if Cam were out of the picture, but I think he would certainly be likely to find someone to talk to, who shared his interests.. and who sympathised. And Diana too, I think in the early years of her marriage, she confided in Barry Manakee, even if there was not any affair going on but the need to have someone kindly and supportive, who understands and shares some of the things you like, and who can offer sympathy when you are unhappy in a marriage, is strong...