Submit paper before or after going on holidays?
I would recommend submitting, because there is a great degree of uncertainty in when you will receive a response, and even with a fast response, your allowed revision time will likely be long enough to extend beyond the vacation time in any case.  If things more unexpectedly quickly, you can ask for an extension and will likely face little problem in obtaining one.

If you do this, however, you have the following responsibilities:


Make sure that you at least monitor your email when you are around, so that you can respond if necessary.
In the two-week period when you will be unable to check your email, make sure you have a vacation auto-response message set up.