It has been a few years since I have travelled that route, but maybe this will be of help.
I assume you will travel Rt. 20 from QC. - then thru Mtl. on Rt. 40 to 417 thru Ottawa and up 17 to SSM.
I have done that from the Ottawa area - both ways - many times. The roads are all good - traffic will be bad thru MTL.
My old home town - Carleton Place show a nice looking camground in RV Park Reviews as Tranquil Acres.
A little further N/W is Pettawawa and Stonecliffe - Stoncliffe shows a nice park in RV Park Reviews.
I think either of these areas are closer to 1/2 way.
Look at your chart - check out RV Park reviews and make a choice.
2000 -F350 -LWB / 2004 Cougar 295EFS.
Barry,Margie & Zeah (the wonder Sheltie)