January should be fine! But not sure about your bike ....
Love the WWOOFS idea. When you get a load of the amount of Pesticides down South you'll gag. (you probably know all this already?) Guess where all our outlawed DDT and other dangerous stuff got sold to? Si, Senor. Hope you can do your best to turn this around while you're there.
The Bike: The KTM 530 is an awesome dirt/race bike, but as stated above, no way a travel bike. It would also be a major target for thieves. Worth a King's Ransom there.
Sell it. You can always buy another later. The money will buy a better and cheaper travel bike that will make the trip with far fewer problems, more comfort and totally adequate for most all off road situations you'll encounter.
I ride dirt bikes with lots of KTM guys and have owned several (KTM Duke ll, KTM 300EXC, KTM 250EXC) The EXC four strokes are not long distance travel bikes. I loved my KTM's (especially the 640 Duke ll, but just not a travel bike. The 530 may be street legal .... but it's still a race bike. (I have a WR250F ... retired "B" enduro rider)
For serious travel I ride a Suzuki DR650. Buy a nice clean used one, low miles. Like an '08 or '09. Pretty inexpensive bike. Read the forums to get info on set up. (count on about a $1000 worth of mods to make it right) and you will thank me from down the road. A great travel bike and pretty fun in the dirt.
The DR650 compared to the KTM is maintenance free. Needs very little, bullet proof and fun to ride ... whether shredding the paved twisty bits, doing fire roads and two track or cruising the highway at 75 mph ... all day, every day. It can carry all your stuff and the sub frame won't crack, frame won't break and the motor is easily good for 50,000 miles given reasonable care.
TIP: long distance travel is hard on bikes. Any bike. It will eat your KTM alive and spit it out dead. Too many miles, too much high speed highway time. If you were doing just Mexico, I might agree with the KTM choice.
But doing the long run down, you need something simpler, more primitive and solid.
Safe Travels!