This is a really difficult situation to be in.
And I guess it all boils down to what you want the most. If you could choose between the life that you have now or, a new life, in a smaller house but in a passionate marriage, what would you choose? And there is your answer.
I chose the latter. I just didn't fancy my ExH anymore. But in fairness he made it easier to leave, as he cheated (a lot). It pushed me to make a change.
I am now married to a man that I am extremely attracted to. We don't dtd as much as I'd like, due to very long working hours/odd shift patterns etc, but when we do it's amazing. Aside from that we are very romantic, kissing, holding hands and telling each other we love each other a few times a day. We still fancy each other a lot, 7 years on.
You deserve the whole package. We all do. But yes, if you leave, there's no guarantee that you'll find what you're looking for.
And it will be disruptive for the kids - lots of traipsing between houses - alternating Christmas - it's a strain and you will feel a lot of guilt. I still feel guilty and I think that will only end when the youngest has left (next year). At the moment she alternates between us and I hate that I've done that to her. I know that she finds all the bag packing a pain in the arse. But she has a stable base here and at least I married someone and didn't introduce her to a string of men. My ExH got a new Partner who stayed for 4 years, but he cheated on her, and now he's alone again. So, kids worry about him, meaning they'll probably want to be with him at Christmas. So, I lose out and I did nothing wrong. Aargh. I hope this gives you an idea of the downsides! You don't say how old your kids are. If they were almost adult, I'd be tempted to wait before you leave.