Yep May baby here too! We found that she would live in gro suits at home, where the heater was always on! If we went out we would put her cute little jeans and pants over the gro suits and little jumpers and tops over the top - just lots of layers and beanies!! Her room has a little heater and stays at 16 degrees overnight so she stays toastie, we used a sleeping bag with blankets over the top.
I kept a nice warm blanket folded over the couch and used my warm dressing gown to wrap around us both when feeding at night! Im surprised that it wasnt as cold or as bad as I thought it would be! In the early days its good to have nice warm deep baths together too as you dont necessarily get all the lovely skin to skin contact you get in summer! Its also a nice relaxing way to end the day together -nice warm and floaty!
Good luck and enjoy the snuggles!