Are you looking to take just the 25% tax free allowance, and the rest into a drawdown or all your pension pot in the UK? I would say the advice your wife got from Aviva was not totally true. You can still get a UK sterling account living in Ireland that this can be paid into.Were you heavily tax taking it as a Lump sum from the UK pension if so could you claim it back being a resident in Ireland.
And as you can see below the state pension can be paid that way, or even into someone elses name, but wouldn't advise against that.
https://www.gov.uk/state-pension-if-you-retire-abroad
What Aviva told your wife, may only be for there policies, but when you "retire" your pension pot, you can take it to other places to get the best return, you would need to speak to these other institutes and make sure they would be happy with this.
Annuity i believe maybe a problem, but drawdown/sipp should still be ok, but things might have changed a little with Brexit.
@mct1 did you just take the pension providers drawdown or shop around, did you have any issues with this, when you said you lived in Ireland?
Think i have abit of studying to do on this myself.