I wasn’t able to make Havdalah on Motzei Shabbos, and I understand I have until Tuesday at sunset to do so. If I rely on that, do I make the whole Havdalah ceremony, with wine, spices, and candle? Or do I follow what I read in the Mishna Berurah and skip the Brachos for the spices and the candle flame? Nusach Sfard (Romanian traditions).

ב"ה Shalom I received your question only yesterday. (Thursday). Nonetheless, you should indeed follow the Shulchan Aruch and Mishna Brura(שו"ע או"ח סי' רצ"ט :ה משנ"ב ס"ק י"ח, שמירת שבת כהלכתה ח"ב פרק נח:כ) and only make the Bracha on the wine and Hamavdil since the candle and spices were instituted for Motzaei Shabbat only. Shabbat Shalom and Chag Same'ach