Congratulations on fruiting in a "cold" climate. I have grown bromeliads (but not pineapples), and my recommendations would be to pot those offsets and wait for possible pupping if you want more plants. Hopefully someone that has actually grown a pineapple will chime in.

I have over 30 pineapples. I am currently waiting on some of them to ripen. I live in Florida so it's pretty easy. I've grown them from tops, suckers, as well as slips. I have yet to grow one from seed. They seem to grow best in the sandy soil in my yard. I do place some compost on them since they grow in part of my garden. I use mulch to help the soil drain out and not maintain the tons of water during the summer here. I use sprinklers on my lawn, garden, and assorted trees. I have a mango, hybrid orange, dwarf avocado, and some banana trees (which grow like weeds). My secret has been planting tons of them. Some pineapple plants die within inches of other pineapple plants. Some grouping thrive near each other. Some pineapple plants die by themselves, others have thrived by themselves. I imagine that the sloping in my landscaping has affected the drainage and that is why some die or prosper. I go to a local fruit market and there is a guy that gives away pineapple tops. I take them and plant them all over my yard. I also plant the tops of the pineapples I grew myself. I am strictly growing them organically. No pesticides on any of my plants, garden, trees, etc. I don't even use fertilizer. The only tree I have issues with is my orange tree. It's never produced fruit after the first year. Hope this helps!