So I feel like a crazy person for even asking this, but I'm looking into ordering linen napkins for the wedding and there seem to be two popular size options, 17"x17" and 20"x20". The 20" ones are roughly double the price. Eyeballing it out, 17" seems big enough but it's hard to tell. Does anyone know if these are good enough or if I should pay extra for the 20"?