The conviction is very recent; that presents more of a problem in terms of Canadian immigration law than older convictions. You'd best get permission before you go. I don't know that I've seen horror stories per se, they just send people back. Presumably they don't take kindly to lying.
Since you have already done so much research, you can probably make up your own mind as to whether to go or seek permission. Here's what Canada has to say about the matter:
If I do decide to travel to Canada, do I have to tell immigration that I have a conviction?
You are advised to carry the final disposition of the hearing - or a copy of your police certificate - or other evidence that no conviction was recorded - as the Port of Entry officer/s may ask you about previous convictions/criminal charges. You are obliged under Canada's Immigration Act to answer that question truthfully - and if you have the documentation to prove you have no conviction recorded it will be useful at that time.
I know I am inadmissible to Canada because of a conviction. What if I just go to Canada and don't admit my conviction?
If your conviction comes to light at the port of entry or during your visit to Canada, you will be reported under the Act and could face removal from Canada and future inadmissibility as a person who has been removed, in addition to inadmissibility due to the conviction. If you knowingly enter Canada while you are inadmissible, then later make an application for permanent residence in Canada, your application for permanent residence is likely to be refused. This applies even if you are sponsored as the spouse or partner of a Canadian citizen or permanent resident.
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Considering you'd thing they'd want to discourage, the language they use is rather wishy-washy ("could", "likely", "advised"). Then, before they discuss lying, they use the word "obliged". Seems you should tell the truth.
If you are willing to risk being sent back then presumably you don't have much to lose by showing up there besides the risk of formal removal and future inadmissibility. Probably not a good idea to lie considering sharing of databases exist.
You could always choose to fly to Seattle and cross the land border; the admissibility requirements are the same, but practical aspect of being refused entry is a little easier to deal with that at the airport.