They have not gone to seed! It takes months for onions to get to the size where they bolt. I would leave them quite a while yet until they get well passed the "crooked" stage before thinking about transplanting them to larger containers (or even directly into the ground depending on your location). They are still sprouting and it looks likes you are going to have an awesome crop!
They are way too small yet to transplant. I am in zone 8a and I have not yet started my onions although it will be in the next week or so. And you definitely can't put them outside yet. I won't be transplanting mine outdoors until the middle to end of April. You should probably wait longer still.