When someone leaves their home within 30 days of Pesach without someone to be bodek it from chametz, they themselves have to be bodek it early (See Siman 436.) In the normal case of bedikat chametz one may not do malacha, eat or learn before making the bedika once the time as come (and even a half hour before) to make the bedika (See Siman 431.) Do these same dinim apply to someone who will be making a bedika early before leaving their house?
I believe not.
The prohibition on eating etc. is because of an obligation.
In the case of somebody leaving early, the obligation is not absolute, but rather depends on a person’s decision to leave early – a decision that can theoretically change. For such an “obligation” the halachot mentioned will not apply.
I have not however found sources for the question, but believe the answer to be the above.