Exactly. For what you'll spend on decent thermal layers, you're halfway to heated gear, with the bonuses of not having your movement restricted by all the layers, and never getting cold, no matter how cold it is, or how long you're out.

For less than $800, I've got a full heated waterproof textile suit with gloves and insoles. That $800 investment turned my riding season into a full 12 months. There isn't weather on this planet that's too cold for me to ride in. Ice slows me down, but the cold never will.

 

WinterSilk has very light and effective long johns and some thick cowboy boot socks from Boot Barn pair with WinterSilk silk socks will do the job for 30 degree or so but below you going to need some heated gear.UA shirts are good get one size larger but long johns to thick for movement.

 

I ride here all year long. Gets down to around 15 F. I of course have Army gear where most may not, but the Polartec® stuff can be found online pretty easily.

Layer 1: Short Sleeve T-Shirt (so I can remove everything as needed)
Layer 2: Polartec® Power Dry® Silkweight
Layer 3: Long Sleeve T-Shirt
Layer 4: Polartec® Power Dry® Grid
Layer 5: Any random jacket that breaks wind and has a 1/2 of padding.

The Polartec® Power Dry® Silkweight's breaks wind REALLY well and holds the warmth in. It also breathes very well so its not too hot once you go inside.

 

I grew up in Minnesota...as kids they taught us that cold was a state of mind...sticks with me to this day...no heated gear...just chaps, a good leather jacket, good gloves, something to cover your face, and willpower :-)