If you are on the BA98 which leaves at 19.55 from YYZ then you are on a Sleeper Service. This means the meal service on-board is reduced in order to maximise sleep. However, a meal/buffet is available in the BA lounge.

Quite a large selection of hot food.

On the CE flight to CPH you'll be blessed with the "Extended Breakfast" service. Don't bother with it.
As the CPH flight is fairly short, around 1h30 min I would have a proper breakfast in the Galleries Lounge. It will be much better. And as you are arriving on a CW flight you can make use of the shower facilities at LHR T5.