@kyle Thank you. Unfortunately it seems that no swap partition is included in my factory installation, so it will take some more effort. However, thanks to your mention of a "constant key" it seems to me that I can have both hibernation and encryption, which would be great. I thought that was not possible a few months ago.
@rik It depends on whether there is a swap partition or not. If you have one, you just have to switch it to be unencrypted (or encrypted with a constant key). If you don't have a swap partition you will need to reinstall and create one.