Another recomendation for the Belt AND suspenders aproach.
To think out of the box , a "belly band" , worn at waist level ( as they should anyway). You will have the reholstering issues inherent to this mode , but a full size pistol can be carried in same position as would be with an IWB , and with great concealment.
Or while still outside the box , a fanny pack, if that wouldn't violate the no pants belt rules. Subject to the usual fanny pack issues , but you could wear one even if otherwise naked.