mortgage term and age

Hi

My husband are I have 17 years left on our 25 year mortgage. We are 33 and 35. We are considering putting an offer in on a house we have seen but as its a much bigger mortgage we were thinking of increasing term back up to 25 years.

Does this decrease our chances of application being accepted? Do mortgage lender have a favourable term/age? 25 years would mean we would be 59 and 60 by the time paid off.

Thanks