Packing the space between the bearings won't necessarily make that grease travel to the bearings. iI've never done it and haven't had any bearing failures so far.
The trick is to get grease throughout the rollers and to do this you either need to force it in with a special bearing packing tool, or use a trick most old mechanics use. Get a handful of grease and, holding the bearing in the other hand (like you'd hold a donut or hamburger), mash and drag the roller face through the handful of grease. Turn to a dry section and repeat. This forces grease into the voids between the rollers, not just on the outer surface of the bearing. Repeat 'til you've gone around the entire bearing. Done right you'll see grease ooze out the inner and outer edges of the roller cage.
Any excess grease will continually re-distribute itself while driving.