Yes, our winter weather in January averages about 34/55F. Of course, it’s a rare day that is exactly average, but we don’t often hit 80F in January, and we only rarely (5 years or so) have a day that stays below freezing.
It varies. Thomasville and mandarins take 4-5 years. Trifoliate hybrids usually take 5-7 years. Ichang lemon seedlings take more than 10 years, which is why grafted trees are the better option.