The calculations in TurboTax assume that the return
is for a full year, and you may not be able to override the amounts it
calculates.
We have another program called Profile, which is
made for accounts, so you can override almost everything. Please aware that the
program is Windows only and only has forms (no interview mode). Also it uses EFILE,
not NETFILE, but you will likely have to paper-file anyway, if you make a lot
of overrides to the calculations. You can buy profile here: https://profile.intuit.ca/profile-onepay/