Ok, I'm going to play Devil's Advocate here. I'm not saying don't delay it, that's entirely up to you, but if you'll need surgery eventually anyway isn't this just delaying the inevitable? The irony is that the best time to have surgery is when you're doing relatively well, which means your body is a bit stronger and will heal a bit quicker, although on the flip side I can understand why you don't want surgery cos you're feeling relatively well. It's a catch 22 situation.
Also, you say "I have finally come to terms, emotionally, with the idea of surgery." No doubt, that will diminish the longer you delay. I'd hate for you to go through all that emotional upheaval again to come to terms with it when you eventually do end up having no choice but surgery.
In the worse case scenario (which probably won't be your case since your doctor seems to monitor you closely) you do not want emergency surgery where they won't have time to site your stoma properly and your body is already stressed enough without adding surgery to the equation.
Just something to consider.
I have had an ileostomy for 31 years now due to UC.