I have 2/3 days between mine Tuesday-Friday and I find the spacing between them good.
That's a tough choice... so is it a case of once a week or twice a week but 2 days in a row? I mean it if it was me 2 days in a row would be better than only once a week. You could always try it and see how it goes for you and explain that you would like to spread it out more as soon a spot becomes available? Depending on what you are in therapy for it might prove beneficial or not.