It is not just the Amps but also the distance and cord gauge. see below.
Even if you move the TT close to the outlet the length and gauge of the cord, (rolled up on the floor) will effect you.
I use a 10 gauge 25' extension between my 15 Amp outlet and the unit and I can run the Microwave or the AC without issue.
Url: Buying Guides: Extension Cords
To determine the cord's capacity, it's important to consider the cord length along with the wire gauge. Every extra foot of cord increases the electrical resistance, which decreases the power the cord can deliver to connected devices. Because of this, it's best to use a cord that is only as long as you need. For example, it's inefficient to use a 100-foot cord to power a device that only needs to extend 40 feet from an outlet.
Refer to the chart below for minimum wire gauge recommendations for different devices and cord lengths.