Took a friend for a belated birthday celebration to Sundara Spa. Was a rather positive experience and here is the synopsis — if and when you find yourself in WI its a place you can go.
Grounds of the spa are peaceful and there are 37 rooms I believe for overnight guests. We had a great day trip with Express Spa services and access to full facility.
The quiet room is a bit tired looking, could use an update but comfy, cozy overlooking the outdoor pool. Yes! even at 48 deg weather it is open. The outside floor is heated, pool is heated and there is hot tub next to it too. Now this is an impressive feature – makes me want to come back when it snows. 
Express Spa package is perfect for a day trip. The practitioners are so good that 35 min are well done. Normally 35 min are never enough for me; barely get relaxing in 30 min. We had massage, facial, and pedi. They use fully vegan organic nail polish, and all of their treatment products are organic. 
While spa services were great and reasonably priced – the food was meh!! Had lunch in between services and lounging; neither dish had much flavor. Later when chatting with other guests we learned people drive elsewhere to eat. We now know why đŸ˜‰ They can improve this, and we recalled how amazing the food at Kohler Spa and Red Door Spa is. So this was a tiny let down.
In any case… if you find yourself in WI and want a mid-level Spa experience Sundara will do great! Look at this… who can complain about huddling around an outdoor fire, cozy and brisk at the same time. 
surprise saffron 