We live in Virgina and many of the advertisements for dog-walkers boast that they're bonded. (I'm not sure how much that means at the end of the day...but it is slightly more assuring than handing your keys to just anyone off the streets, at very least this person is bonded with the state)
Also meeting with the potential dog-walker before hand can set your mind at ease. Although they could just be a good actor/actress, you'll probably get a good/bad vibe from them.
However if you're unable to find a suitable dog walker, it is possible for a dog to regularly hold it for 12+ hours. The key is to gradually train them to go longer, in the time before you switch, start going to the gym or somewhere else before coming home, so that they begin to expect to wait longer. As long as it's not an older dog with bladder issues, it's not unreasonable.
You might want to confine (with baby gates or doors) the dogs to an area with hard floors--like the kitchen, while you transition them to the longer days. Just make sure they have toys/bones to keep them busy. At first you might want to not leave out water for them--just make sure they have plenty of access to water while you're home, as they get more used to when to expect to go out, you can give them more freedom and water while you're gone. I would highly advise against crating a dog for more than 6hours, unless it's a last option (they're being destructive, or possibly getting into things that could hurt them). The hardest part will be the transition, but remember dogs are creatures of habit, and once they realize they get to go out at a set interval, they adapt quickly.
Even after you're dogs have adapted to a new schedule, it's probably a good idea to have a dog-walker that you can trust (to some degree), since sometimes our dogs get diarrhea--and when that happens I do crate them and have a dog walker come midday.
I used to worry about leaving the pups alone all day, but I'm fairly certain they just sleep
since every time I've come home at an unusual time--they're just sleeping