You could not travel, but if you are on Aer Lingus (or get transferred to Aer Lingus) your bags may well go to Dublin anyway. If your DUB service is BA, your bags won't go to DUB, but retrieving them in LHR could take weeks. So go HBO or try and change the routing to go via LCY or LGW. This would be allowed if your flights suffer a cancellation or a big time change. Bags via LGW and LCY have to returned in LHR.