I have a beautiful little avocado that I have grown from a pit. It is in a fair sized container and has grown to just over 12 inches, and there are more new leaves coming at the top. I have brought it in and placed it on my landing windowsill because it is getting rather cold in my garden room, which is unheated. But the roots are growing out of the bottom of the pot. When should I transfer it to a bigger pot, and have I done right bringing it inside?