Has anyone had luck with growing a "Rosemary" plant in the house all winter? I know that it is susceptible to mildew inside.

Not me. Rosemary for me has to be outdoors and I've only found one type that will live even then. I'm not very lucky with rosemary.

Rosemary can be difficult, but not impossible to grow indoors if your winters are too cold. What does them in, typically is the dry heat indoors. Or I've seen folks place them on the fireplace mantle and kill a plant in less than a week. Ditto for being under the vent of a heating system too. Try and keep your plant as cool as possible indoors, an unheated sunroom? and any/all available light. Do not overwater

My rosemary that I brought in bit the dust. The one I left outside is doing beautifully.

Last year I successfully wintered-over my rosemary, it even blossomed for me.

This year, I kept it in a different spot and it's already dead.

Yes, the trick is cool temperature for it, where I had it last year was right in front of my sliding glass doors that are always cool and east-facing so they got a lot of morning sun. And let it dry thoroughly between waterings.

I think since we have fairly mild winters I will just let them stay outside and on the porch.

I have a rosemary plant that I've had inside for 4 years. I must admit that it is one of the most neglected plants I own! It sits on a west facing drafty window and only gets watered when it starts to droop. But it is doing well and flowers for me once a year.