I have a 30 gal tank (115 lt) And I moved house in the middle of December. (And in Canada, the average outdoor temperature can be pretty cold.)
Anyways, we moved the entire rest of the household (I wouldn't let my father and his friends move the tank without me there, and I worked the whole weekend we moved.)
The heat had been off in this house since Sunday morning, and the doors had been open all day with people moving, but the tank was still at 72, which was only down a little from it's normal 75, which I was very impressed with, because I had my winter coat on the entire time I was working on the tank.
So on the Sunday night just me and my father went back for the tank. I've done the math, a 115 lt tank weights about 450 lbs full of water, whis doesn't include sand or ornaments, just straight tank and water.
So what I did was bring a 15 lt bucket with me. I took out about 90 lt, there was only a few inches of water left in the tank. Then I took out all the fish out and out them in bags that I had saved from getting them from the pet store. Then I took out as much of the remaining water as I could. Then i took out all the larger decorations, I have a lot of drift wood in my tank, I took that out, but left the plants in.
Now I don;t know how heavy that tank was, I personally think it was too heavy

My father and I lifted the tank and took it out and put it in the car. (Keep in mind, I'm a 20 year old girl with a pretty fine build)
We got it to the new house. (We brought the bucket of fish and the container of hardware too so it was all in one trip.
I decided I wanted the tank in the basement, which was finished. I wanted it there because there are only small windows, and in the old house I had a lot of trouble with algae because there were two floor length windows.
Anyways, the tank had an inch and a half of water logged sand, and getting it down a flight of stairs was the worst workout I've ever had.
Now that's just how I did it, and it's just a suggestion. I didn't loose any fish (And I actually left 1 cory in the tank because I didn't realize he was missing, and even he survived.)