[ubuntu] Can an upgrade 2 versions from the current be done and not reformat the drive?

Hello all,
I've searched this forum and could not find the answer.
Briefly, I am ruing 14.04.3 LTS Trusty on my Dell Inspiron 1525 160GB HDD laptop.
It literally took me years to move off 10.04 LTS and get a better distro.
When I decided to do that, I assumed that I couldn't go from 10.04 to 14.04 without doing a back up, and reformatting the 80GB drive.
So I did a clean install of 14.04 on an empty 160 HDD and then coected the 80GB drive exteally, by USB,
and transferred a load of files to the new drive and the newer Ubuntu 14.04. Very time consuming.
However, I noticed when I upgraded to 14.04 LTS that there was a 15.04, a 15.10 and a 16.04beta that exist beyond 14.04!!
I thought, well, I'll upgrade to one of those someday, when I get a new 250GB drive and then I'll have to do the data transfer thing all over again.

That day has arrived. My 250GB SATA drive is being shipped to me as I type this and I expect it any day now.

My first question is: Can an upgrade, 2 or 3 versions higher than the current be done and not require a reformat of the original drive?
Second question: Am I going about this the long way or the dumb way or otherwise wrong way?
Third question: Are there Ubuntu tools that can make all this easier?

I'd like to use a more streamlined method of upgrading Ubuntu when it's time, and preserving my data and backups.
I'd like some suggestions. I'm open to change, I just need to be sure of myself when I commit to a big change.

Shobuz99