Go on a weekend when the forecast is for good weather, take the three season tent, do short miles, and if the weather turns and snow is piling on, plan to be awake all night knocking it off the fly. Come out the next day, process the experience and decide if winter camping is worth it to you - then start to draft the budget for winter gear.

My winter shelter is a GoLite Shangri La 3 - a tipi shelter that weighs 2.5 lbs with the big aluminum center pole. It's floorless so I can dig in and use a stove inside, has vents, and the shape sheds snow and wind well. Single wall shelters (depending on where you are going) are popular in winter. Condensation is not even on the list of things to worry about. Your clothing, sleeping bag, and sleeping pad should be. Layering a CCF pad with a three season sleeping pad should suffice, but rent a winter weight bag if temps are expected to be below 20F.

I recommend reading up on winter camping and the skills necessary, and clothing and gear considerations. You should always have a shovel, if "winter' for you means a lot of snow. With a shovel you can always dig a trench or snow cave in a pinch.