Offensive Coaching Change?

I guess this is more of a question than a serious post, but recently there has been a lot of talk about drafting a backup QB and letting Peyton play 1 or 2 more years; while there are arguments for and against this I am more interested in how would a coaching change specifically an offensive change affect Peyton if he decides to come back. Although, most of the time Peyton seems to be the offensive coordinator he is not; he does have a lot of say in what takes place, but there is much more to a coordinator. With a new coordinator typically comes a new playbook as well as a new philosophy, with Peyton only having 2-3 years at most to stick around it this league how productive will it be to make major changes on the offensive side given Peyton's comfort with the current offense. Please give me your thoughts.