You can run MyEtherWallet offline / locally by going to github and just placing all of the javascript in a local directory.

Here is the link, that was shown in the old MyEtherWallet page

1. go to https://github.com/kvhnuke/etherwallet/releases/latest
2. click on vx.x.x.x.zip
3. move zip to an airgapped computer
4. unzip it and double-click index.html
5. MyEtherWallet is now running entirely on your computer.

Here is a video showing how it is done.