Using Flow to send time based emails and re-evaluate criteria

Is it possible to use one Flow to send emails x, y and z days after an opportunity is updated to meet criteria, but also have the later emails re-evaluate based on fields updated when the earlier emails are sent?

We've used workflows and time-based workflows in the past and had issues where someone has amended the opportunity so that it triggers the workflow again, re-sending the series of emails.  I really want to prevent this, so want to update 'Email 1/2/3 sent' fields so that if they are populated, it won't re-send the email. (No matter what the user does to the original record!) Also, if someone should close the opportunity, the remaining emails must not be sent.

Is it possible to achieve this:

IF (for all actions):

   Campaign name is Renewals AND

   Record Type is Commercial AND

   Stage is not Closed won or Closed Lost AND

   Primary Contact email not blank AND

   Email 1 is blank 

THEN

Send email 1 

Update Email 1 field to TRUE

14 days later

IF:

   Email 1 is ticked AND Email 2 is blank

THEN

Send email 2

Update Email 2 field to TRUE

14 days after email 2

IF:

   Email 1 and 2 are ticked AND Email 3 is blank

THEN

Send email 3

Update Email 3 field to TRUE

I can't see how to re-evaluate after each action. Do I need to just create 3 different flows or can I combine them for neatness?  I've looked at subflows, but they need to be autolaunched so I can't set criteria.

Can anyone point me onto the correct path please?

Many thanks