That can be easily arranged in three steps: 
1.lead the human Rainbow Dash through the portal. 
2. Teach her to fly. 
3. Dress her up as a plushy and fly with her.

Figures. Rainbow Dash finds herself so awesome that she just has to have a plushie of herself.

@Sandblast  
Looks like the URL broke with the merge. Repost for posterity:  

@G-Rex  
Who doesn’t!!

@Sandblast  
needs that plushie :3

“When She Loved Me” comes to mind…

Daring Do fell in the bottomless valley.

@Spiritus Arcane  
Yes

@Lawful Girly  
That’ll work. X3

@shionshy  
Go to the source and save it on DA!

I wish I could fave or upvote this pic twice!

i nerver say daaawwww but… DAAAAwwwww

@HamburgerTime
 
Wow, that is amazing.

@HamburgerTime  

 
:P

Must…..have…..plushie………HNNNNNNG

Only RD would cuddle with a plushie of herself.  
Relevant:  

Despite actually being a pony who is surrounded by other ponies during the course of a normal day, she still cuddles a pony plushie at night. This is adorable, and its pretty easy to relate to Dashie here.

Watch the plushie beat Rainbow Dash in her dream.
 
Next morning:  
“Rainbow, why is your plush in the trash?”  
“Because it cheats.”

One night, Daring Do.  
The other night, herself.

@Bhazor  
Oh god, I;m an enabler!

@kircher
 
HA HA! JOKES ON THEM! THIS IS MY FETISH!

@Mellow91  

Now that’s what I call “playing with yourself in bed”!  
waits for incoming tossed rotten tomatoes

Of all of Uotapo plushie pics these are Definatly. The. Best. Possible. Plushies!