We have camped at least once in every month of the year over the past 6 years here in the Pacific Northwest.

We remote camp via 4x4 with our little ones.

The tent is a 9x12 Heritage Weathermaster by Coleman because:
it stands up in the wind
it takes only one person to set it up (in under 5 minutes if you're moving)
I can get dressed standing up and not on my knees
and the whole family fits

As for sleeping bags we love and trust the Sumberjack sleeping bags. We went with the Woodsman series and got the Big Timber -20. (they sell a -40 too). We like the rectangular bags because they can be zipped together. This is a huge deal when family camping as sometimes the really little ones have a hard time sleeping in their own bag. They are larger bags but the flannel lining is great when the temp dips down at night. I don't plan to be out when it is below zero but the extra warmth is comforting.