I am a man so I can't give very specific advice, but I did travel with two female companions on the Trans America (73 days) and they were able to manage. I got the impression that they found it to be an annoyance, but not a huge obstacle. I am not sure when during the trip they were menstruating, but am pretty sure they managed in some places where there were no facilities for at least a full day and probably longer.
We also traveled with two other ladies part of the way and they used oral contraceptives to avoid menstruating for the duration of their tour. I have no idea of the health issues if any of that or how long you can do that, but I think they were on tour for something like 80 days.