My sincere hope is that they get back together. Hopefully their time apart will make them appreciate each other more, what they had long ago, what they can have again, even richer, more full. As the old saying goes ~
absence makes the heart grow fonder. And now that Albert will be getting married, hopefully Caroline will have more time to do other things, one being spending more time with her husband.
After all, their children are grown & flown the nest, except for little Alexandra, and now they can enjoy their golden years together. Indulge their individual & combined passions, be it architecture, gardening, riding horses, visiting museums, attending the opera or ballet, dancing, renovating their estates, whatever makes them happy, and what they didn't have time to do before because they were too busy raising their children together and fulfilling family obligations (e.g. Princess Caroline being First Lady of Monaco for almost 30 years; something thrust upon her at such a young age due to the tragic death of her mother in 1982).
Lol, also they have the joys of grandparenthood to look forward to as well, and the planning of their children's marriages eventually. I would imagine it would be more pleasureable as a couple versus a singleton.
Lastly, hopefully the affection they have for each other is still there, because they can build from that. The first blush of youth is gone, as well as lust, what remains is friendship...and affection.
PS: in Caroline's case I am reminded of the old saying ~ first you marry for love, second for security, and lastly for companionship.