You get the Quest Items of a Ribbon and Dazzling Christmas Ring for turning some of the quests, the Carrots one and one that I can't remember right now. You get the Red Stubs that you may or may not be using up.
You get the Ice Hat for fishing in that one square with the tiniest little fishing holes.
You get a second Christmas Tree for your house for turning in some quest.
Your Profile number of CI's increments by several even though you get nothing for the quests that said you would get an Elf Hat, Santa Hat and Candy Cane Sword and Reindeer Pet.
And you will get something else, perhaps a new Pet in a few days, we all have to wait till that happens.

that's it.

Thanks Raymond - I had gotten them all I guess then - well except the ribbon, but I'll have that one in time - I've been going pretty slow on that carrot thing. I've seen the ice hat and wondered about that - I had no idea about the fishing hole Glad I asked.

Don't thank me. Someone else saw it first and mentioned it here, at least 4 squares/half days before I even got to that square. And I didn't bother to fish there myself until I was done every square.
I do think it's shameful that the Developers made it so inconspicuous. Everyone should know about it, but not everyone reads these forums.

which area to fish, can anyone tell me please?

Someone just got Rudolf's Red Nose, but I don't have it in Inventory nor was it any item in my Winter Wonderland zones or for purchase.

I don't think it's a bad thing that it's inconspicuous - it's a reward to those who actually take the time to enjoy the fishing aspect of the game. Plus, it shouldn't be too much of a surprise - every unique type of fishing spot has had at least 1 item assigned to it.

The fishing hole in ice is interesting, it doesn't follow a pattern of values like the others do, it's kind of like a mix of all the other holes combined.

Yeah, I remember getting Rudolph's red nose, but it's not anywhere in my inventory. So I looked back through (many!) play history pages and found I got it by whacking a bush on Dec. 14th. Where it went, I do not know. Maybe one of the items required at the crash site??

All my quests are long gone from the completed quest log.
I thought that people here were talking about something that we get to keep, from fishing or otherwise won from this event.
There were/are 10 things, one from each of the 10 Christmas Squares, to get to complete that square instead of a Puzzle Monster. I had forgotten about those already, but they add into our Profile number of monsters and number of puzzle pieces collected even though these squares are 'temporary'.

Unless you put things into some room of your house, all your unplaced house items are guess what, in the ''unplaced house items bar of your inventory. Did you look there?

I guess so because my second one is among the 30 or 40 things in my Inventory that I have no room to put into my House.
But here's an experiment, remove your old Tree from you House and see if that goes to your Unplaces House Item section of your Inventory.