Hi Lou, it's great to see you here at ATP! I'd love to see photo's of your Wardian Case's too! I've always wanted one but have so far just stuck with the glass jar terrariums and converted aquariums.
I agree with what has already been said. If the soil is staying moist and the plants seem to be adjusting, it sounds fine. Like Lee Anne, I've had a problem with too much condensation in my enclosed terrariums and end up having to remove the lids on occasion to allow for a little air circulation to dry them out or they end up with way too much moisture inside and plants begin to rot. You may notice more condensation in your Wardian Cases during the warmer months. Please keep us posted on how they are doing and share photo's if you can.
Lin