This is a great topic for discussion because there is no fixed answer and everyone comes across similar situations frequently. There is no fixed answer because so much depends on the person's hand size, finger length, and practice history. For those with small hands, there is often no choice: you must use the fingering with the larger reach.
Several observations:
(1) for most people, 1-4 has a larger reach than 1-5. However, this advantage is more than negated by the fact that 1-4 octaves require an additional hand twist, which creates stress. Therefore, if you are comfortable 1-5, it is better from the standpoint of relaxation, which is paramount.
(2) your comfort level also depends on how you first learned it. Some teachers insist on finger changes in situations like this (for better articulation), and if you learned it that way, it is perfectly OK. The most useful rule here is, don't keep changing and trying different fingerings! Early on, or as soon as possible, experiment and decide on one fingering and never change it! If you are not sure and keep experimenting, even occasionally, this problem will bug you forever. This factor slightly favors 1-5, the simplest solution.
(3) changing fingerings puts an extra load on your memory, especially if you haven't played in a while and you want to brush it up. This factor also favors the simpler 1-5.
As for the repeated thumb, remember that the time signature is 2/4, so they are not all played equal.