Hi L.,
Yes, I believe that it is possible to get through the week and NOT wean. I also believe that that would be a desirable goal. So I have some suggestions.
You could probably find some very good answers to your questions on the following websites...
http://www.llli.org/
http://kellymom.com//
http://forum.kellymom.net/
My brief suggestions for you would be.... to pump twice a day while you are gone--if possible at approximately the same times of the day that you would be nursing at home.
I also suggest that you use a Medela pump, since I think that they are the brand usually preferred by midwives and lactation consultants as the most effective. So I would suggest renting one if you don't have one--the electric kind that working mothers tend to buy (Pump n Style).
www.medelabreastfeedingus.com/products/breast-pumps
I also suggest that each time that you pump, you pump on both sides simultaneously, since that seems to be the more effective way to keep up your milk supply (more effective than pumping one side at a time)
I also suggest that when you get back home you spend at least 48 hours doing the plan for increasing your milk supply, and that is to eat more, drink more, rest more, and nurse more.
I do suggest that when you get back, you offer him the breast, and if he refuses it, I suggest that you follow the LLL suggestions for "a nursing strike", which is a situation that babies and toddlers can go through and still come out the other side nursing, if the mother follows certain suggestions.
http://www.llli.org/search?cx=012805113672795732671%3A72a...
I also suggest that you do things to help him through his grieving process while you are gone, so that he might be less likely to have a nursing strike when you come back....like calling him a couple of times a day, leaving a recording of your voice for him to listen to any time that he wishes while you are gone (perhaps including lullabies that you sing to him at night or nap time), leaving breastmilk behind for him to have in a bottle (perhaps at the same time as he's listening to your recording), and perhaps leaving a t-shirt that you've slept in for a few nights for him to smell and sleep with while you are gone, and perhaps leaving some small item with him to "take care of" for you while you are gone, and anything else that you can think of that might help him to feel connected with you and reassured that you will come back. You might also leave a calendar behind where his father or care-taker can go through some kind of ritual with him every morning, to cross off another day and show him how many days there are left until you return. You and others can probably come up with many other ideas to help him to feel connected with you and hopeful that you still exist and will come back very soon, with some kind of way to communicate that to him on a level that he can understand.
Best wishes,
J.