I'm sure there are people out there who have gotten really creative with popsicles... guarantee there's one out there with avocado in it, lol.
I've made popsicles by mixing coconut milk and fruit juice. I did it last year and I don't remember the proportions I ended up with. Might still be more sugar than you want, but at least it's less than using only juice. This year I want to try pureeing fresh fruit and mixing with coconut milk.
This recipe makes me drool: Blood Orange Creamsicles: Refreshing and Sophisticated | Family Kitchen - and also shows that you can do yogurt and fruit juice mixed together, although it might be a little tart from the yogurt, as you can see by all the honey they end up using in the recipe. I'd leave out the honey and try it, and if necessary, I'd add a little stevia.. but I know a lot of people here avoid that, too.