Onions from seed?

Ouch
You'd need to be able to supply some warmth and lights to start them that early. Early Feb works about right for me for seeds.
Sets are a lot easier to get going but I get a lot of bolting especially with reds and I also like the wider variety choice with seed.
You could maybe try sowing direct or in modules outside around middle to end of March if you have some seeds left and the will

Last year was the first year planting on the plot and I grew sets, still eating the onions so we were well pleased with the returns

I'll see where I am towards the end of March before deciding on seeds. With all the different perennial alliums I have on the go I may have my hands full