I just had a similar experience. That side of my family is all really conservative, church-going people, and I haven't seen any of them in like 15 years. I quit going to the family gatherings a long time ago for various reasons, and missed all of their weddings and stuff.
I spent a lot of time worrying about how things were going to go, and talking myself into being afraid, but when I got there they each told me several times how happy they were to see me and that they'd missed me, and I got a whole bunch of hugs, which I love. That was all really nice, but now that I've reconnected if they reject me due to the trans thing it's going to be pretty devastating. I'm not out to any of them, and except for one friend of the family who says he didn't recognize me everybody else was like oh I recognized you immediately! So it's nice in that the first meeting wasn't tainted by a bunch of "omg you're trans" drama that would've been hard to deal with, but also reaffirming my own feeling that I haven't really changed at all.
Oh well, we can't live our lives in fear or we won't do much living. I hope things go well for you, and I'm sure I speak for everyone here when I say we've got your back no matter what happens.