Call the DMV where you live and where will the trailer be ultimately registered (I assume NY). Many states have the ability to get a 3 day travel permit for $10 or so and that solves your problem in state. However, I would not attempt to cross the border either without plates or with plates from a different trailer. Plates are automatically scanned at most US/Canada border crossings these days. Check with customs on import requirements as you may be required to pay an import customs fee and that is separate from DMV fees. Better safe than getting your trailer confiscated. Also, don't forget the boat registration or licensing if crossing the US/Canada border. State to state that isn't a problem as long as you aren't launching it in a state without having it licensed in any state.
Some states require boat inspections to prevent invasive species transport across state lines and those are often at port of entry truck scales. I got my boat in Colorado (titled and licensed there) and transporting it to Washington state, I had to have it inspected in Utah, Idaho, Oregon and Washington for invasive species. Invasive species inspections sites don't look at license but you might have to pass through a truck scale as part of the site.
