4.69% fixed for 5 years is a pretty sound deal but would be better if you could get the same over 7 years with no ties at the end imo!! There may be an interest rate cut in Feb or May but no gaurantees of course so be lucky.
As to having a bigger house, i'm sure most of us would want the same but not at the expense of a large debt as no home is worth the financial strain that is put upon a relationship in such cases imo.
Anyway none of us know your financial position so it may not be that bad in the first place, so best of luck to you and your family.