Only for OrganizationData.svc to be availabel through https no IFD is required. I only had to configure Web Services in Deployment Manger to use https AND by what ever reason I had to remove the http binding from IIS for the site. After I removed http binding OrganizationData.svc was availabe via https, than I added back http for the site and stil could access OrvanizatinData.svc via https. I found a post in the internet which did the same, removed http binding in IIS for the site to make it work.
IDF is a very different topic, I don't think it has anything to how the WebServices are accessible. It implicitelly deals with https, but it's not required for WebServices to listen to https.