find a cave close by; either troll cave or catacomb. build a base in its opening (block the entrance with panels to stop you entering) for an instance hugely well protected base.
then stock it with arrows and survival stuff and a portal.
also before you summon him set camp fires all around his base and a few workbenches; these will ensure he cant summon his minions to annoy you during the fight and just make things that little bit easier.