For my specific case - the law abiding solution seems to be to have the dealer get me a 31 day non-resident registration from Minnesota (where we are picking it up).
That will be good enough to show in any state for 31 days if we get pulled over. (Incidentally, trailers of this size in MN need to be registered but get a sticker not a plate. They'll give you a plate if you request it, but that's to keep other states happy)
https://dps.mn.gov/divisions/dvs/Pages/ ... n-ResidentThen with title in hand, I'll need to FedEx that title back to Virginia where I can have someone (my lucky father in this case) go to the DMV
with a special Power of Attorney (
http://www.dmv.state.va.us/webdoc/pdf/vsa70.pdf) to title & register the trailer in Virginia.
(Since I'm buying a manufactured teardrop, it'll have a proper VIN, etc and shouldn't have a problem getting registered)
Then he can mail me the new plates somewhere out west. Hopefully that can be turned around within the 31 days.
Thanks for the advice - I agree that we're not likely to get pulled over, even without plates on the trailer, since the tow vehicle will have out of state
plates and I'm hoping that police officers have better things to do than to worry about whether Virginia requires trailers to have plates.