Sure, but we know from the setup and I think it is fair to just assume a constant velocity which gives us this countably infinite sequence of distances and time

Sure, but we know from the setup and I think it is fair to just assume a constant velocity which gives us this countably infinite sequence of distances and times, both getting shorter geometrically. And their partial sums have a finite limit. In essence you seem to be stuck because you have to complete an infinite number of tasks, but that is just the wrong measure, i.e. you must measure the time or distance, not the number of tasks in order to determine if you can complete all the tasks. Just walk from start to goal, there is no task in Xeno's infinite task list where he could say that you did not complete it. The problem is that Xeno can not give you the complete list of tasks if he tries to enumerate them one by one, not that you can not complete them all. Instead of enumerating them, he should just tell you to visit all places 2^-n for all natural n, you walk one meter and are done.