Helping Iggies through a truamatic change???

My son who is currently living with us has two italian greyhounds.He spoils them rotten and they sleep with him every night.He is going to be going away soon for at least 5 months and leaving the dogs with us.
I know this is going to be very very hard on them as they are very attached to him.
How can I help them through this??
What can I do to prepare them for this change? I worry they are going to start peeing everywhere as we just barely have a handle on that.

They cant sleep with me as I have a boston terrier and a chihuahua in my bed as well as my hubby so there just isnt room.
Thanks all...

He should start training them now to sleep in a crate, not in his bed. That will make thing much easier for everyone concerned. It may be difficult for him, but he should start crate training right away, so that they will have become accustomed to their crates being safe happy places to be when he is away and when he is around. Have they had any such training yet? Gradual adjustment is the key.

We just adopted the one ig in July and she was crate trained then.But she doesnt really use it now.We have two open crates in the house that they can sleep or hide in if needed and they do use them on occasion.Especially if they have bones and want to hide.
I dont know if I can get him to make them sleep at night in the crates.That is going to be very hard to hear them whine and its so cold and they love to curl up under the blanket right next to him:(.
But i know when he goes Im going to be paying the price.

Start now! Just have them spend first an hour, then two and work your way up to the whole night - buy ear plugs if you have to! YOU need to be strong and consistent. Make the crate a fun place to be, toss a toy or treat in to encourage them to go in ... the whole positive reinforcement thing. And whatever you do, NEVER let them out when they are fussing or whining, wait until they are calm, or you'll create monsters!

It may take a while but its probably best to crate train them. I was always told that these tedious hours spent crate training will save you hundreds undoing any unwanted behaviour and possibly thousands replacing things that have been broken. All the best, I'm sure it'll be fine!