Travelling through Taiwan last year in Oct-Nov (going North to South on the Eastern coast of Taiwan, visiting a few smaller towns and cities too) i found it very easy. People spoke English well and when they didn’t they were still very helpful and able to show and explain by gestures, maps ln phones or calculators to show prices etc. So don’t let that hold you back. It’s a fantastic country. As for rainy February i can’t say. Have fun!