I don't remember the exact size of the mini-blind off hand and Maxwell is "hibernating" right now. I believe it was about 30" wide x 24" high, but I would suggest measuring your window anyway because, from my experience, even if the trailers were the same model & year, the windows could be different sizes. We were at a rally this last summer with thre "exact same", '64 GlobeTrotters, and each of them were different.
With regards to the bathroom...we haven't had a problem with the curtain getting wet (or moldy, but we are in arid Colorado, not much mold anywhere)...but we are both adults, (no kids) and are careful not to get it wet. We went back and forth on the drape vs blind and decided to go with the drape for now, who knows, we may go back & put in a mini-blind someday. The concern with the blind was water spots & corrosion or rusting of the mechanism. Another thought we had and may do someday is a roller shade....for now the drapes are fine.
Does your Caravel
have a separate shower compartment off to the side or is it the kind that includes the whole toilet area in the center of the room? I would think this could make a difference too...does the window area get drenched or is it off to the side (like ours).
I have more pictures & descriptions on our webpage (www link below) as well as a link to the supplier of our blinds in the "During" section.
Good luck with whatever you decide to do!