I do not know if that species is self fertile. Only some agaves are, and to varying degrees. If it was blooming away from other flowering agaves, it probably selfed. If it was surrounded by other flowering agaves, or there were any within the flight distance of a hummingbird (or whatever) for that matter, you likely will have to wait until the plant is bigger to know for sure what you've got. Regardless, it will likely resemble the parent to some degree (intermediate phenotype) if it is a hybrid.
Assuming the container has holes, it's good for a few months or so, or until the baby seedlings become crowded. Better to leave them alone for a while and then when they have 2-3 adult leaves (or more), they will be more likely to have good roots and survive the extraction/transplant better. The transparent container should give you a good opportunity to inspect the roots before taking action. I usually plant agave seeds at about twice that depth (and wait maybe 6-9 months to separate) but I don't think it really matters. Lift the lid when they start producing their first true leaf (or sooner, if the seed leaf grows too tall) but do a fair amoint of misting afterward to keep the top soil layer from drying out completely.
I have no experience with the coldness and wetness that you have there, but I would assume the seedlings are sensitive to cold, probably even temperatures above freezing for that matter. Do you have a sunny southerly facing windowsill that isn't already full of plants?
I would think you need to protect them from temps much below about 45 degrees F until next winter at the earliest. Just a guess there. Go ahead and test the limits if you want, just be prepared for a possible sudden meltdown.
