First time there coz It's not far from my place. 
my Suggestion to adjust the set menu for Wongnai as ppl normally order fondue not just for one person.
be more creative with set menu I'm sure you can play around with it , well just think from the customer side or behavior. Food are ain't that bad but to fulfill customers might need more details on that. 
the decoration and atmosphere are quite nice very cozy place and available parking. Good to go with bunch of friend and the grand piano are lovely.
The sauce quite nice for the fondue but the spaghetti many little too spicy ( must put chili Icon ) if it's gonna be that hot.