Trump/Pence out after '18, Prez Pelosi resigns, Hillary is incumbent in '20...

[Blue3]

Let's say Trump and Pence are both caught up in the web of lies, and are impeached and removed soon after the 2018 elections by the Democratic congressional majority.

Nancy Pelosi is sworn-in as President, pledging not to run in 2020, and nominates the winner of the popular vote in the last election as her VP: Hillary Clinton.

Pelosi accomplishes a few things she always wanted to, helps get some legislation she especially wanted through, helps clean things up after Trump, and then she resigns in mid-late 2019. Single-payer healthcare and free college are passed, so are $15 minimum wage and paid leave, and a few other big things. Hillary Clinton is sworn-in as the 47th President, with about 18 months before the 2020 election and she decided to run for (re) election.

How goes 2020 with incumbent Hillary versus whoever the Republicans put up?

[Blue3]

I mean, there is a lot that is implausible about this scenario, but Pence being impeached before he picks a replacement VP is pretty unlikely. 

Oh I know it's implausible. Just wondering how an incumbent Hillary would fare in 2020.

(and I imagine that Pence would be removed before Trump, and they wouldn't confirm a VP replacement if named).