Is the homestead under attack? If so, it is by design that no new portals are opening; end the attack (doing something in northern Luculla; speak to Zixzax or check your quest log) to open the remaining portals.
Did you not get the dialogue with Astarte or the demon when you entered the ice portal? Or did you get it and use Rift Travel to leave, rather than return to the main section of the homestead through the portal?
Did one of your characters end up in the ice area earlier in the game, due to a glitch when teleporting in or into the homestead?
That will cause a problem with the dialogue that should be triggered when you later enter properly.
If you are playing on PC, please email supportdos@larian.com with your latest save (or a Dropbox or Google drive link, etc); there is a workaround that can get the rest of the portal to open.
Each save is a folder in the '..\Documents\Larian Studios\Divinity Original Sin Enhanced Edition\PlayerProfiles\<ProfileName>\Savegames_patch' folder.
In Windows Explorer you can zip a file or folder by right clicking on it/them and selecting 'Send To | Compressed (zipped) Folder' (and similarly in OSX/Finder).
On console (as well as PC) there is an exploit that can allow you to proceed past the Source Temple door, but you would miss the experience and traders in the later homestead portals.
Drop a teleporter stone in front of the door (I got it to work dropping on the left side, a few steps back), then move it from there past the door (if necessary, rotate the camera to see; you may need to move the cursor around a bit to find a place where the pyramid is outlined in white and you can drop it); see the screenshot below. There is a waypoint just past the door, which you can use to leave/return.
https://www.dropbox.com/s/igf6rls5tol2zea/DOSEE_Source_Temple_door_workaround.jpg?dl=0 
