I've been wanting to do these feats for a a bit, so I figured now is as good a time as any. The first will be a range based feat (this will affect the results of some calculations if the size is accepted). The second is a new lifting strength feat. The last is a potentially massive upgrade to the speed of the top tiers.
Rarities Magic Range[]
Multiple times Darkanine has calculated the energy for Rarities storm, this time I'm making an upgrade not to her power, but her magic range. This will scale to Twilight Sparkle in all her keys, and any other relevant Unicorn. I'm going to calculate the size of Ponyville. I'm taking a statement from the episode "Too Many Pinkie Pies" wherin Pinkie Pie runs back and forth from The Watering Hole and Sweet Apple Acres. She mentions that she needs to shave off 20 minutes off of her time and she'll be fine. This implies the full trip takes longer than 20 minutes. I'll assume 10 minutes to Sweet Apple Acres and another 10 minutes back to The Watering Hole. I'm also going to assume Pinkie Pie is going at full sprint. She wants very badly to be with both Rainbow Dash and Applejack, and she is trying to shave as much time as possible off her trip, I heavily doubt she'd be going at regular speeds under these circumstances.
Low End (Accepted)[]
In "Griffon the Brush Off" Pinkie Pie is depicted as able to keep pace with Rainbow Dash. Rainbow Dash is typically depicted as one of the fastest Ponies in the show (not withstanding the top tiers). According to this, the highest speed of a Horse top is 54.7 mph which translates to 24.45309 m/s. This times 600 seconds makes Ponyville 14.671854 km wide.
High End[]
Rainbow Dash is actually a flier, being a pegasus and all, so I'll try using the speed of the fastest Bird: The Golden Eagle which according to this site can reach a top speed of 320 km/h. I am using the Golden Eagle over the Peregrine Falcon as the latter can reach 389 km/h, but only when diving and not normal flight. This would make Ponyville 53.33334 km wide.
Lifting Strength of the Pegasi (Accepted)[]
"In Rarity Takes Manehattan" a storm begins. https://www.dailymotion.com/video/x5vm6p5 Feat happens at roughly 5:58, in which a giant storm overtakes Manehattan. We don't see what exactly created the storm, but we do know for a fact that Pegasi are in charge of the weather, and as shown in multiple episodes, they directly put the clouds together by hoof, and destroy them directly. In "The Ticket Master" we initially don't see any Pegasi creating a storm, but it turns out they assembled it from above the clouds and thus out of sight. So, it wouldn't be too far fetched to assume that Pegasi are pushing the storm clouds together.
The storm covers all of Manehattan and beyond, so I'll assume a radius at least half the length of Manehattan.
A = pi x R^2. Manehattan is clearly based on Manhattan, so we get a length of 10,800 meters. This gives the storm an area of 366,435,367.115 meters. As this is a thunderstorm, I'll assume the Cumulonimbus thickness and go with a height of 8000 meters. Which makes the volume 2.9314829e+12 meters. Multiplying by 1.003 to get the mass and we now have 2.9402774e+12 kg. However, this wasn't done by a singular Pegasi. In my Winter Wrap Up calculation, there were 71 Pegasi clearing the blizzard. I'll assume a similar number here making the final tally 41,412,357,545.5 kg or Class G.