South Georgia and South Sandwich Islands is about 150 times bigger than Tuvalu.

Tuvalu is approximately 26 sq km, while South Georgia and South Sandwich Islands is approximately 3,903 sq km, making South Georgia and South Sandwich Islands 14,912% larger than Tuvalu.
Tip: This to-scale comparison of Tuvalu vs. South Georgia and South Sandwich Islands uses the Mercator projection, which distorts the size of regions near the poles.
Compare further: South Georgia and South Sandwich Islands vs. Tuvalu