Here in PA. you can register the trailer for 6 years at a time, but, of course, you do pay six times the one year registration. So, for example I have one trailer that carries a 12 dollar registration fee and it costs 72 bucks for 6 years. I find it worth it to do and the State will do it on line.
The hull can be registered on line for the same price as mail-in and you get a certificate good immediately until the stickers come in the mail. Unfortunately this is still a 2 year registration and it expires in March. But still, it is very convenient for the next time. Good luck and have fun with your rig.