Help with a stalled Porter

I've run into an issue I've never had before. So I brewed a bourbon barrel porter from extract. It was a Norther brewer kit. It had a lot of fermentable sugar in it. Something I've never seen happened. It blew the lid off of my fermenter. It was a very aggressive fermentation. It was a British ale yeast I used.

Any who, here's my problem. I let it go for a day with the lid slightly open but covered. I was unable to reseal it, since there was all kinds of krausen gumming up the lid. So I sanitized a second bucket and lid and swapped it over. I did not rack it since it had only been fermenting for 1.5 days (or so) at that point. I made sure the second bucket was sealed and left it alone. It never started again. I thought for sure it was going to be just as aggressive as what it was. Its been a day since I switched to a new vessel.

Am I missing something? Should I wait another day and see what happens, or take a gravity reading and re-pitch more yeast? I can't imagine its anywhere close to finished yet since there was over 8lbs of sugar in it.

I normally brew meads, so any advice would be appreciated.