Well I'm not an expert LOL, but I live in your zone. I'm not sure there is anything you can find to bring in during the winter months, unless you like holly/coniferous things to decorate with! I suggest early blooming bulbs like tulips, daffodils, and hyacinths. Not only do they come out first but they smell like spring. I also have a good amount roses around my yard, when the tulips have stopped blooming the roses usually start. A bushy rose like knock-outs are hardy and bloom practically until the first frost in my experience.

I live in zone 7b. You can grow forsythia but it will bloom later, but can be forced indoors earlier. Also nandina is beautiful in winter. Camellias can bloom fall to spring, depending on type - sasanqua or japonica, one is more cold hardy but I can't remember which. Hellebores bloom in winter. It seems like I had some old flower heads of oakleaf hydrangea and limelight hydrangea. Tulips and daffs are great too.

Annual cuttings I like the most are Sweet potato vine, green and black. I have recently gotten coleus and I think its amazing, especially if you dead head it. I also like purple heart. All 3 of those varieties can have cuttings taken from them and placed in water, but all 3 wont do well during a freeze so you'd have to take them inside for winter and reroot every year, but they do spread profusely.