Open bar for the whole reception?

Hi, Ladies. We are getting married at a small upscale hotel in our area. Our wedding package includes 3 hours of open bar. The first hour is during cocktail hour, then the bar closes for dinner. The bar reopens after dinner for another 2 hours. The package also includes a champagne toast for every guest. I know it is horribly tacky to make guests pay for drinks, which is why we went with a venue that included an open bar in their price. We really don't have it in the budget to extend the open bar for more time and I'm not sure if it would even be necessary! I think some of our guests will already be leaving 2 hours after dinner is over. My question is, do you think this is enough alcohol for our guests?