Statistics Canada has Special Interest Profiles that let you obtain a lot of very obscure data. So if you want to know how many Anglicans rent their homes in Saanich or how many people of Jamaican origin commute to work by public transit in Whitby you can find out!
https://www12.statcan.gc.ca/census-recensement/2021/dp-pd/sip/index.cfm?Lang=E
Here's the 20 most common ethnic origin combinations (looking at the "Irish" group for example allows you to what other origins Irish respondents declare):
English and Scottish 1,833,805
Irish and Scottish 1,745,140
English and Irish 1,651,690
Irish and French 805,830
English and German 789,175
English and French 716,150
Scottish and German 662,390
Irish and German 644,005
Scottish and French 617,555
French and German 414,085
Canadian and English 285,775
English and Ukrainian 242,760
Canadian and Scottish 226,910
English and Dutch 223,475
Canadian and Irish 222,560
Ukrainian and Polish 219,765
German and Ukrainian 219,365
Scottish and Ukrainian 212,420
English and Welsh 206,185
Irish and Italian 190,440