The impact will be substantial. If you have a credit monitoring service, you'll be able to answer that question by watching how your scores change in the next 30 days.
One quick thought, though. It sounds as though you may have been unable to pay off your credit card debt in a long time. If you could do that, you'd have already been able to easily answer what your scores do when your utilization goes down to 5%. You'd just pay down your cards and see.
Instead, your method of lowering your utilization was to extend your credit limits. So congrats on having higher limits -- but I encourage you to work on paying off your entire CC debt and and then pay your CC bills in full each month. When you do that, it's easy to expreiment and see what you scores look like at 1%, 5%, 8%, 15%, whatever. More than that, it enables you to start setting aside substantial amounts of your monthly income towards savings, rather than always being in debt to CC companies.
Just a thought. Congratulations again on having the higher CLs.
