Ask questions, meet dancers, and be part of the conversation.
I think the skill level also matters.
I agree. I am 5' 7", closer to 5' 9" in my dance shoes. I regularly dance with 2 guys who are 6' 4". They're both good enough dancers that I don't have any problem even though they're 9" taller than me.
Last year, my partner was my height but had shorter legs than I do (I'm a leggy lady). I think that matters as much as height.