A lot of effort has been put in to try to define what is on topic and what is not but in general the ‘rules’ here, as on all SE sites, are inevitably somewhat flexible – if for no other reason than that they are mostly set by the community, one that encompasses a range of opinions. The result is that there are not really any rules at all, other than ones set by SE relating to the mechanics of site operation (serial voting, time outs etc), that are almost identical across all SE sites. Within any one site, like Travel, we just have numerous guidelines. Indeed so many some overlap or conflict.
Flexibility is appropriate because our objective is to help one another rather than to enforce laws set by a ruling clique. However there is a need to balance the benefit to a specific individual with the benefit to the world at large. I might be highly appreciative of an answer to my question about the cheapest flight from A to B this Monday that saves me a lot of money relative to my own best search effort, but come Tuesday the answer is of no use to anyone else (unless it describes a general, reproducible improvement in the search approach I took). 'My' question is about travel but allowing it on TSE would just inconvenience others, mostly not community members, who may be seeking a similar solution over the years to come.
Without much by way of written constitution there is reliance on ‘case law’. However of those launched, TSE is a relatively new site and has yet to build up as much precedent as many others on SE. Even the biggest/oldest, Stack Overflow, is still not ‘solidified’. There have been some major changes there in the last year and minor ones are ongoing. TSE is still trying to define more closely that grey area at the (imprecise) boundary between on and off topic – and hopefully will continue to narrow it down (even reposition it) for a very long time ahead. Meanwhile there are anomalies. TSE has over 15,000 users and in most cases five of these is enough to decide one way or the other. On or off topic may depend on only little more than which five.
Why was this considered off-topic
It was a matter of some users opinions. There really is no reliable yardstick for an ‘independent’ measurement of those opinions against ‘rules’. We know who voted to close and that at least some of those five considered that “This question does not appear to be about traveling within the scope defined in the help center.” Surely an exact answer can only be given by those five?
It would be reasonable to consider here whether those opinions were representative of the views of the wider community but I suggest not worthwhile in the circumstances. I’m afraid it seems to me that a major factor is often not really “this is not on topic” but more, from those with the privilege of voting to close, “I don’t know the answer”. For that a rewording of your question, probably as a new post rather than an edit, might help. To emphasise a “road trip in Canada, especially about the backcountry “ and deemphasise a fairly narrow spec for a travel forum.
Alternatively, there is one SE site Software Recommendations that is rather distinctive for SE in appreciating requests for recommendations. It has some very specific requirements but also, being in beta, is (I presume) still feeling its way with what is or is not on topic there. But I suggest 46 hits for forum is:question closed:0
makes this prospective.