We have stayed in Tuvalu a couple of times, on the far side of the resort. Our youngest daughter did not have a problem with the walk to the TTC (she was 5). From the far side of the resort to the TTC, if you walk at a reasonable pace it is probably 10 minutes (the Poly is not a huge resort). Personally we would be too impatient to take the monorail around to the TTC. Once you wait for a train, and it makes its stops at GF, MK, CR, around to the TTC you're probably looking at at least 20 minutes. We have taken the resort monorail back to the Poly at the end of an Epcot day though since it's just one stop and tired feet dictate choice!