Okay that sounds decent, might be worth the drive. Do you know how the ranges are run by the ORA?
Check out the ORA website
https://ontariorifleassociation.ca
Be aware the these are usually a whole day commitment. Starting at 8 am for range set up and safety briefing. And be prepared to help tear it down and clean up, usually ending around 4 o'clock in the afternoon. Some groups stop for lunch, some try to shoot right through. Bring plenty of water, snacks, lawn chair, sun screen, hat, ammo.
If the heat index is too high the base will shut the ranges down. This is beyond the control of the ORA. It is also possible that the ORA gets bumped off the range due to military requirements, again beyond the control of the ORA. I would advise contacting the ORA via email the day before the event.
Speed limits on base are strictly enforced, easiest way to get to most ranges is through the Lisle gate.
Some group require you to do butt duty(pull and mark targets) some groups use electronic targets, some groups use paid markers. Bring some cash $20-$25 if paid marker are used or for the cost recovery of the electronic targets.
You can get lunch on base at the Canex, there is a pizza joint, Timmies and a Subway.
Bring a rifle suitable for the event, ie. your .30-30/SKS would be great for a plinking event/sporting rifle event, not so much for a day that will only be shooting 1000 yards.
Also if you are using a muzzle brake, let the match organizer know, so he can squad you with others shooting a muzzle brake.
Hope this helps.