They have both been up before; they are both former military in the USA, and they will have experience with deployments from both NASA and the military not going to plan, considering the mission of this one they will have known about the possibility, but also when you are an astronaut/cosmonaut things like this come with the territory of the job and something they are prepared for.
They will have plenty to do up there, they are both capable scientists, have experience living up there, and the ISS has all sorts of food, the Russians send up a lot of tinned stuff and the Americans send up dehydrated food and MRE style food, fun fact, the salt and pepper they have is liquid form, so they squirt it onto their food rather than shake.
They will still be in contact with their friends and family, they all have laptops in their bunk space, they can email, message etc, they can ring their families and videos calls are often set up. If they get bored of that and their crew mates, the ISS has ham radio, they often communicate with random people with ham radios on the ground.