HI TMS,
In my opinion we don’t really have any good “top roping” ice climbing areas, at least not that I can think of.
Two areas close to Reykjavík that would probable work out as “top roping” areas.
Tvíburagil
Lekandi, the routes in the gully above Lekandi are to long to top rope but you can go above them and maybe rappel half way down or something. (remember to ask the farmer for permission to park your car and walk over his lands.)
We have all of our registered ice climbing routes on our webpage.
Hope you find some climbs that suits you needs, have a good time.
Best regards,
Ottó Ingi