I would be pretty hesitant to take a "new to me" used boat offshore overnight without some serious assurances that everything worked as it is supposed to and I knew everything that needed to be known about the boat.
Inside, on the ICW, you're never too far from help. Not so in the open ocean at night.
Personally, like others have suggested, I find ten hours to be a really long cruising day. It's not so bad if you have someone to take over for a few hours. When starting out on trips, we often cruise nine to ten hours on the first day because that takes us to good anchorages. After that, i's usually far less, five to seven hours, depending on where we want to stop.