I checked on a whim as it was just after 6am and I don't know why, but I thought maybe something might open up. We're going the 31stJan-9th Feb and so far it has all been unavailable. When I checked this morning, the after party was available on 1st, 2nd, 3rd, 4th, 6th, and 7th. Unfortunately when I look now it's only the 4th and 7th but given they opened up today, more might open up @6 tomorrow?
And I found it by searching fireworks dessert on the portal.
https://disneyworld.disney.go.com/e...owland-terrace-after-fireworks-dessert-party/
Meanwhile, the preparty is available everyday of the first week of Feb:
https://disneyworld.disney.go.com/e...d-terrace-fireworks-dessert-party-plaza-view/