You are correct that Toontown in the Magic Kingdom will be closing on February 11 to make way for some major enhancements to Fantasyland. But don't worry, you'll still be able to get lots of quality time with Mickey and his pals. The Mickey, Minnie, and princess greetings are being moved to other areas of the Magic Kingdom. The Tinker Bell greeting is being relocated to Disney's Hollywood Studios. And you'll still be able to meet many other favorite characters throughout the parks.
Since some of this is still in flux, you should be sure to grab a free Times Guide (located near the maps) when you enter the parks. The Times Guides give the hours of the regularly scheduled character
greetings at that particular theme park each day. For example, the Magic
Kingdom Times Guide will tell you exactly where and when Mickey will be appearing. In addition to the regularly scheduled character
appearances, there are many surprise or impromptu character greetings.
When I was at WDW last month, I saw Daisy Duck hugging guests on Main
Street. This was not noted on the Times Guide or anywhere else.
Similarly, there are character visits that are part of some of the tours
or other special events, as well as at character meals. You can make reservations for a meal with characters by going to the Disney World website
HERE.
While there is no master character guide available to guests, there is
resource available to Disney cast members called the "character hotline."
If you are looking for one specific character anywhere at WDW, I would
go to the Guest Relations office
at any of the theme parks. Ask them
to call the "character hotline" for you. The character hotline will be
able to tell them if any particular character will be in the parks on a
particular day, and if so, where and when the character will be there.
Good luck and have a magical vacation.