Why is this so hard? When climb rate falls to <500 fpm or so and you're losing speed just tell ATC you'll need to level off. In the summer, full, on hot days (ISA +15) this will be around FL280. You can get higher with a step climb if you need to do so. Usually within a few minutes of leveling off you'll have gained plenty of speed for another 2000 or even 4000 feet.

I have nearly 10,000 hours on the CRJ-200 and we all know that CRJ stands for Climb Restricted Jet.

Our charts tell us what the airplane will climb to based on weight and ISA deviation. I usually subtract 2000 feet and say that's about it. If I need to climb higher later I can once I've regained some speed.

Why leave yourself with no options? Why give up horizontal speed just to gain altitude? The airplane flies better lower anyway.

Just my $.02 based on 11 years in the airplane in question.