Right now you're trying to get into that portal, and I can understand that. If I were having trouble with Safari (and by association the iOS 8.0.2 update), then I would try to isolate the problem this way. First, Safari has been changed with this update to its current state. Now, what you don't know right now, is if it's the current state of Safari (as its been updated) is the problem, or its something squirrely on your own setup, as it is right now.
If I were to test it out, I would want to check the operation of Safari on another iOS device (one that someone else says that they are not having a problem with) and see if you can access that portal through Safari. Or, you could go down to the Apple Store, grab one of the display units which will be running the current version of Safari and see if you can sign in there.
If you can't, then you've got a problem with Safari in its current upgraded state. And with that, I would go to Customer Support at Apple and report the problem. They'll do an update that will correct the problem you and others are having with that specific issue.
And in ordeer to work around that problem (if that's the problem you're having, that is "with Safari"), then I would try another browser at the app store. Sometimes another browser will not have a particular problem with a particular website that Safari might be having.
However, if you find that the current version of Safari is not the problem (by testing it out on another iOS device that is operating fine, or trying the Apple models at the store) ... then that means you should probably restore your iPad to its factory default setup. If Safari operates everywhere else (on other iOS devices) and doesn't have a problem, but you do on your device, then something squirrely his happening (probably something got corrupted in a setting or a file), and you need to restore everything to a factory default condition. This will make your system "new" as if it came off the factory floor that day.
Be sure to save all your data to a backup, though, before you start fiddling around with everything. At some point, after you've tested out the factory default setup, you'll want to restore your own data. For testing purposes, don't restore your data right at first. Just test out Safari on your new setup with your portal.