Is there any place in Canada where big steam is running anymore?
I don't think so, and there aren't even that many smaller engines running either. Going from east to west:
Nova Scotia, P.E.I, Newfoundland & Labrador: None (the latter two have few or no railways).
New Brunswick: Formerly the Salem & Hillsborough operated an ex-CN ten-wheeler, but they went cold years ago.
Quebec: Delson (Canadian Railway Museum/ExpoRail) have never had a large engine running, and even the John Molson replica has been down for at least a year. Over in Gatineau the Hull-Chelsea-Wakefield railway suffered washouts in 2011 and ceased operations then. Last I heard their equipment (including an ex-Swedish steam engine) was for sale.
Ontario: The South Simcoe Railway operates ex-CP 136 (of National Dream and 'Tripleheader' fame) and Waterloo Central has a 0-6-0 switcher. SSR also has a CP 4-6-0 (1057, also part of the Tripleheader) but she has been cold for nearly 20 years. No big mainline excursions since CN 6060 returned to the west circa 1980.
Manitoba: Prairie Dog Central's ex-CP 4-4-0 is the only steam here. I believe the two privately-owned 4-6-0's that were shipped up from the Eastern U.S. not too long ago are stored here, but of course would require a lot of work to run again.
Alberta: Several operations here. Calgary's Heritage Park operates three ex-U.S. Army switchers (0-6-0?) on a loop, Fort Edmonton Park has a 2-6-2 originally from the deep South, the Alberta Railway Museum (where I volunteer) operates our ex-CN 4-6-0 1392 on a 0.5 mile demonstration track, and finally the Alberta Prairie Railway runs ex-Mississippian #41 (2-8-0) 20 miles from Stettler to Big Valley, which by my count is currently the longest steam run in the country (eek). Alberta Prairie also plays host to 6060 (now owned by the non-profit Rocky Mountain Rail Society) when she is running, but unfortunately that has not been the case since 2011 due to much-needed boiler repairs. Last I heard RMRS had raised about 2/3 of the money needed to fund the repairs, but will not be up and running until summer 2018 at least. She is the largest operating steam engine in the country when running. Oh and I almost forgot the now moribund 2816 in Calgary.
British Columbia: Near Cranbrook Fort Steele has two engines, a 2-6-2 and a Shay (down for repairs) which run on a loop, in the okanagan the Kettle Valley Steam Railway has ex-CP 3716 (2-8-0) on a small section of remaining track, in Kamloops their heritage railway runs ex-CN 2141 (2-8-0, recently back in steam) on a CN spur (formerly they ran all the way to Armstrong before Kelowna Pacific went bankrupt and EHH came to CP), and to round out the mainland the West Coast Railway Association maintains Royal Hudson 2860 in Squamish, but they have not gone on a major run since before the Winter Olympics (2009?). Over on Vancouver Island there are numerous logging engines preserved at Alberni Pacific (2-8-2T and a Shay) and the B.C. Forest Discovery Centre in Duncan, which has (!) seven (Shays, Climaxes, 0-4-0T). Not sure how many are operable though.
Finally last (but certainly not least) is the most remote operation of them all, but also easily the most popular: The bi-national White Pass & Yukon with their 2-8-2's and steam powered rotary plow.
I never thought about it much until now but the Great White North is pretty bleak for steam, especially once you get east of Alberta. I think that about rounds them out, let me know if I forgot any.