My history with strollers is this - my son dumped his stroller when he was less than two years old. I know, not normal but he walked everywhere. We took our granddaughter, my son's stepdaughter to Disney when she was five and I bought her an umbrella stroller where her stuffed Stitch rode more than her but it was nice to have especially at the resort. We then took my then five year old grandson who, like his father, is a walk happy kid and we did no stroller and he was fine.
However, since your child is turning five and you are thinking about an umbrella stroller and not a huge one, I say take it just in case. If your child surprises you and doesn't need it, no big deal. But if your child does need it, a huge relief for you.