That's a tough thing to do, I can only imagine! That's why I am not getting any big tanks for myself now because I will be moving too in a couple of years, or even sooner. And if you have a big tank, it's really hard, if not impossible, to move it great distances. How large is your tank? What kinds and how many fish do you have in it?
I am sure there is nevertheless a way to move your tank, even if it's larger. Carol and Gunnie will probably tell you what to do and how to do it

I personally think that the weather (the temperature outside) is a big factor when moving fish. You could simply put them in a plastic bag for a quick car trip, especially when temperature outside is warm and stable. But I am not sure what to do when you're moving such a great distance. Hmm ...