I go through this all the time. I change my water every Saturday and dose from Sunday through Friday. Whenever I have to travel, I usually do water change in 2 weeks. but I add the same EI dose on alternate days. or I will do the first dose and then travel. It works for me. But its not as good as the normal schedule for sure. I also reduce a few hours of lighting everyday for the 2 weeks of travel.
I personally wouldn't worry about a few days. I would double dose before you leave and leave everything else the same. EI provides quite a lot of room for error in regards to nutrients. Remember, EI provides quite a lot of nutrients. If you start trying to change everything just for a week off you're asking for trouble. Plants will be impacted more by altering lighting and/or CO2 levels than anything. Small changes in nutrient levels for a week? Not so much. Plants like stability.
I tried to leave it as it is for a while but the problem I ran into was shedding of leaves. When I get back, I see a lotta leaves with holes and floating. I did try double dosing and it worked at times but mine is a 20G and some of my plants are sensitive to CSM+B.