I am departing WDW on Jan. 18th but checked Weather.com for your forcast on the 19th. It doesn't look especially promising..high of 69 with 60% chance of rain. Of course, in Florida, that means rain some time during the day - not necessarily ALL day long.
If you are lucky and it isn't raining when you are in Epcot, I would recommend the Rose and Crown with a table on the patio. (you can't reserve this, but you can request it when you check in for your reservation) If this is of interest, try to make a reservation ASAP. The later, the better, as you are assured a front row seat for Illuminations. These late seatings are hard to find.
You didn't say the ages of your party, but my kids are 10 and 11, and love the "make your own sundae" for dessert. The food is good, the wine and beer are excellent - and the patio is the place to be. If raining, the you might enjoy the inside amusement and buffet of the Biergarten.
Edited to add that my 10 year old eats like a baby rabbit and the price of his adult buffet is something I avoid, which lends itself to my choice.
Good luck and have a great time!