Lengthy power outages for some northwestern Ontario residents may also impact cell services.
Tbaytel says it has plans to use backup generators and battery power in an effort to maintain service.
It is warning some customers could still experience poor service or none at all.
Scheduled maintenance by Hydro One will result in three separate outages.
One is west of Sioux Lookout, impacting Frenchman's Head and Lac Seul, impacting about 400 customers from 6 a.m. to 4 p.m. on Saturday.
The other two will occur on Saturday.
The entire town of Fort Frances, Couchiching First Nation, and areas to the east as far as the unorganized township of Farrington will be without power on Sunday between 7 a.m. to 5 p.m.
A separate outage on Sunday will impact an area between English River and Borup's Corner, including Ignace and north to Savant Lake.
The power will be out to that area from 6 a.m to 5 p.m.
