You can sow them in containers using the winter sowing method. I would suggest soaking the seed first over night. If you start them in something like a milk jug, they will be protected or at least portable if this spring continues to freak on it.

Morning glory will be fine. You could throw the seeds out in the middle of the winter and they would be fine. In fact, I had morning glory planted at my house by the previous owner. I moved in four years ago, and I still have to pull it out every spring. The seeds are tough!

It's not a matter of sowing, it's a matter of germination. Iopomoea seeds are tough and self sows very nicely. However, if we have an unusual warm spell followed by a freeze, they will easily germinate and get zapped. Seeds will be fine, but seedlings will be killed. If you have a ton of seed and want to direct sow - go for it. If you have some purchased seed you have your heart set on, consider being more conservative.