Hi A.,
It's always wise to check in with the "experts" on child development on a question like this one. Here's what Dr. Spock says about separation from an infant (article below). I hope you'll reconsider this trip or take the baby with you (maybe a friend or a grandparent could come along to give you some much needed alone time).
-R.
http://www.noblemother.com
Separation Anxiety
by Dr. Benjamin Spock
reviewed by Robert Needlman, M.D., F.A.A.P.
Infants
If a mother goes away for a number of weeks (to care for an ailing relative, for instance), her baby of six to eight months is likely to go into a depression, especially if the mother has been the only caretaker up to that time.
The baby is visibly depressed, loses her appetite, is unresponsive to known and unknown people, is more often found to lie on her back just rolling her head from side to side, no longer tries to sit up or explore her environment. If the separation is short, the baby will recover completely once her mother returns. It may take time--days or weeks--for mother and child to get back on track.
The best way to deal with this problem is to avoid it whenever possible. If you have a choice, don't stay apart from your baby for longer than, say, 8 to 12 hours at a time, during these early months. It's probably a bad idea to plan a "parents only" vacation weekend when infants are quite young.
If you know a separation is coming up, help prepare your baby by getting her father, or another care provider, more involved before you leave. That way, your baby will have a trusted figure to rely on. If you find that you need to go away suddenly, take your baby with you, if you can.