Sliding the saddle all the way back is probably more about how you sit... likely very upright. And how your body wants to balance over the BB due to other aspects of how the bike fits you.
Though everyone likes the sexy aesthetics and racing looks of a road bike, you might actually like a proper cruiser style geometry bike with a slack seat tube angle. Though it's hard to find what I'd call a proper cruiser style bike any more. And they generally are less expensive builds on the heavy side compared to road bikes. But for 60 minutes of riding at a comfortable effort the weight really isn't an issue if they are appropriately geared.