From MK the Poly would be the 3rd stop... CR - TTC - Poly.
There is also a boat you can take from MK to Poly which may be a little bit quicker.
From Poly to TTC for the Epcot monorail it is a short walk to the TTC... 5 maybe 10 minutes tops. The monorail would need to make almost a complete loop to get back to the TTC.