Regarding your first query about IELTS expiry at the time of ITA, there's another work around but terms and conditions apply:
IRCC website says that if there's a change in your profile after you receive an ITA you have to make sure that the change is reflected in your APR but first you need to recalculate your CRS score. If that negatively impact your CRS score i.e. your new CRS falls below the lowest CRS of that draw in which you were granted the ITA then you should reject your ITA and go back to the pool nd update your EE profile. (Instructions from EE Ministerial Instructions)
But, like in your case, if you manage to score the same in IELTS as your previous score, then obviously your CRS remains the same and you can go ahead with submitting your APR but you must make sure that you mention the changes since after ITA we cannot update our profile.
Refer this page, if still have doubts:
https://www.canada.ca/en/immigration-refugees-citizenship/corporate/publications-manuals/operational-bulletins-manuals/permanent-residence/express-entry/invitation-apply.html