By bulbs I presume you mean rhizomes? If the rhizomes are dormant or almost dormant when you planted them then I would keep them in a cool place like the garage until you can plant them in the garden, which would be as soon as a the ground thaws. The rhizomes won't be hurt unless the entire pot of soil freezes, and that is unlikely in your garage now, in fact, soon you will want to move them outside at least by day to prevent them from getting too hot and sprouting too early. If the plants are actively growing and above soil level then that's a problem and you basically have to grow them inside until hard freezes are over, then plant outside. I grew them (both the white "grandiflorum" and the red "erectum") for many years in an Ottawa suburb when I was a kid. I had them in a small north-facing garden up against the house and they basically grew and multiplied and were happy. Their natural setting in Ontario is in hardwood forests, where they bloom before the leaves come out on the trees (so semi-shady), then leaf cover from the trees becomes quite dense by the end of May so they spend the summer in deep shade. The ground doesn't freeze very deep in trillium country so I would probably try to plant them in a north exposure up against a house so that the rhizomes don't freeze too hard in winter (or give them lots of snow or mulch cover). Definitely in shade. Some pics I took of trilliums in the wild... Patch of Trillium grandiflorum: Individual Trillium erectus (these don't often form patches, more like scattered plants:

Trilliums are very common native plants here in the PNW and they often grow naturally in woodsy rural areas. But they are commonly sold in garden centers as well and all different varieties and colors. These are not wild harvested plants but commercially grown specimens and are adaptable to any shady garden situation. Just an update, but my trillium Volcano discussed above made its move without issue and thrived in my friend's garden for several years before he graciously shared a chunk with another friend. And that plant took transplanting well and has thrived also. Now that I have moved from a full sun beach location to one where I am more shelterer by trees and with considerable shade, a chunk of that plant is coming home to take up residence with me again!! So three moves and at least one division did no harm at all.

I don't know about Trilliums, but jacks CAN skip a year, though it is usual. The corms would still be firm though. You received these in May? I wonder if rather than sending you dormant plants ready to sprout in 2016 that the vendor took 2016 plants, removed the foliage and shipped. If that is the case they will not sprout until 2017 anyway. I love our native jack and have it here and there in my suburban garden, where it slowly spreads and sometimes appears in surprising places as seed gets spread around. Conditions here are "average". It certainly seems adaptable and can take some drying in midsummer where it generally dies down anyway. I have a couple Trilliums but they have not done as well for me.......persisted and bloomed for many years but not really increased in size much.

Re Trillium: Have had several clumps T. grandiflorum and T. erectum (local trilliums) growing in our garden for maybe ten years. I tend to have planted them at the back of the mixed perennial beds, in part, so I won't disturb them. We water the whole garden as required. Looking at the trilliums in the local woodlot; you don't see them in waterlogged areas (e.g. where there are seasonal ponds), but rather on the likely well draining slopes in the dappled sunlight before the woods leaf over. The literature seems to confirm the need for drainage; however, surely ground waterlogged, for a few hours, doesn't matter.