I suspected it when you said "semi-detached". I'm in T.O. too and owned a semi for a number of years.
Leave the heat on, make sure it reaches any "cold rooms". Sometimes there is a cold room built under the front steps -leave the door open.
Set timers for the lights.
Check for flyers or misdirected mail in the mailbox frequently. If you have a mail slot, even better.
Make sure the snow is shovelled!! You can be fined by the city if not. Maybe come to some agreement with your neighbour if you share a driveway. If there is a big storm, the snowplow might block in the driveway a day or two after the storm, so check that frequently too.
Check with your insurance provider that they know the house is unoccupied. This might affect your insurance rates.
Depending on when in April you move in, you might need to start cutting grass or raking by the end of April.
Go in to check the interior frequently too. Sewers can get clogged, water pipes can break even if not frozen. If caught quickly, it's not so bad. If left for weeks.....
Make friends with the neighbours and let them know your move in date and give them your phone number.
That's all I can think of for now - Happy homeownership!