Blimey, it's like watching vultures at a will reading at a funeral, some of these comments! And I'm totally with you on the snobbery comments too. Must be wonderful to have so much money that you can turn your nose up at a "cheap package holiday"! And for those who say holidays always cost more than you think, well, yes, they certainly do in the UK. That's because we don't have the all-inclusive deals you might get in Spain or Greece, just as examples, and it's also because everything in the UK except some food is extortionately priced. Especially accommodation and travel.
I think the most sensible suggestions have been those who suggest you get a few valuations and then decide from there. Look at it this way: it's all energy, in the end. Things are just trapped energy. So, if you can, take that energy and transform it into something you need. Which, in your case, is a holiday, a break, a clear end of an old chapter/beginning of a new one, from the sound of it. If you want to preserve the memory of the object, take photos of the ring to preserve that energy, which is what I do when I get rid of things.
When my dad died he left very little in the way of worldly goods but he left my mother an excellent pension. She scrimped and saved all her life, and never enjoyed herself, and in the end, when she got dementia, every penny of that money, which Dad had worked hard for all his life, and had already been taxed when it was deducted from his pay packet , was used to fund her care until it ran out and she had nothing. And I mean nothing. I would honestly rather she had used that money to go off on round-the-world cruises and had a hundred boyfriends and had some pleasure out of life while she still could rather than sit looking at her bank balance and company shares like some descendant of Scrooge. Much good did it do her when she was no longer compos mentis enough to recognise her family, let alone go and have a good time somewhere.
If you do find that what you're offered isn't going to be enough for what you need, is there any other way you could fund a holiday or a break? Would instalments be an option, for instance? It might sound a little cynical, and I don't mean it to, as I have huge sympathy for everyone involved in the Thomas Cook debacle (except a few of the top bods who must have known what was going on, but that's a different conversation) but there should be some very keenly priced offers out there at present.
Whatever you decide to do, it's your decision, your life, your memories,. But you sound like a sensible lass so I reckon you already know that. All the best. 