“Eastern Orthodox” is an umbrella term that is used to generally refer to all the Orthodox Churches collectively. Each Orthodox Church is distinct. Russian Orthodox is not Greek Orthodox, but they are both Orthodox.
Regarding reception of the Eucharist, Confession, or Anointing:
Can. 844 §1. Catholic ministers administer the sacraments licitly to Catholic members of the Christian faithful alone, who likewise receive them licitly from Catholic ministers alone, without prejudice to the prescripts of §§2, 3, and 4 of this canon, and ⇒ can. 861, §2.
§2. Whenever necessity requires it or true spiritual advantage suggests it, and provided that danger of error or of indifferentism is avoided, **the Christian faithful for whom it is physically or morally impossible to approach a Catholic minister **are permitted to receive the sacraments of penance, Eucharist, and anointing of the sick from non-Catholic ministers in whose Churches these sacraments are valid.
§3. Catholic ministers administer the sacraments of penance, Eucharist, and anointing of the sick licitly to members of Eastern Churches which do not have full communion with the Catholic Church if they seek such on their own accord and are properly disposed. This is also valid for members of other Churches which in the judgment of the Apostolic See are in the same condition in regard to the sacraments as these Eastern Churches.
So, unless it is physically or morally impossible to approach a Catholic priest, you cannot receive in the Orthodox Church from the Catholic Church’s point of view. Seems it’s highly unlikely that you meet these criteria.
Please also note that even though the Catholic Church says you can receive under those grave circumstances, the Orthodox** do not **allow Catholics to receive the Eucharist in their Churches.
So, it’s really a moot point.
