Actually you don't have any scope except to raise objection against the set-aside application.
If opposition party claims it based on fraud, summons not served/served to wrong address or any other cogent reasons as 'facts in issue' for set-aside app, then you may/should not ideally get any oppotunity to disprove the 'facts in issue' and unless this application is NOT alleging any 'fraud committed by you in winning the ex-parte' decree but giving some affirmative excuse for abscentism.
More or less, it adopts the liberal view unless it is a blatant misuse, disregard of the due process and subjects the party to pay costs.......thats it!!!
once the set-aside application is filed, then until it is allowed by this or upper courts, it will be pursued uptill SC, which means you can't remarry Anyways !!
Once it is allowed , your main suit is reopened and again that would be pursued upto SC by either of you!