See question above. Is there a better way to do the Sheva Brochos on that night?

As mentioned above, some Poskim are stringent on Asara Beteves more than other Fast Days, as we wrote on question 1973 and1566 regarding being machmir to fast on Asarah Beteves more than another Taanis and therefore, even someone who because of age and weakness does not fast besides Yom Kipur and Tishaa Beav, should fast on Asara Beteves, we wrote: “Beis Yosef (O.H. 550) quotes Avudraham’s opinion that if Asara Beteves was to occur on Shabbos we would fast on that day, since it is similar to Yom Kippur in which the pasuk mentions “Beetzem Hayom Haze” (Yechezkel 24). Toras Chaim (550: 4), wonders why Bais Yosef would mention the above detail since it does not have a practical difference, as this fast day cannot according to our luach coincide with Shabbos. He explains that it may be for the purpose of being more stringent on this Taanis than others and other prohibitions, such as washing also apply. He mentions that his own father, the Machane Chaim, on the end of his life, when he was very weak and was not supposed to fast, he forced himself to do so on Asarah Beteves. Biur Halocho (551: 1) mentions that some maintain in Asara Beteves the stringency of the Nine Days. Bnei Isoschor (Teves14) explains that this fast day marks the very beginning of the Churban and all the days of Avelus that we maintain, and is therefore more severe and strict. However, in practice many Poskim maintain that one does not have to be more rigorous than in other fast days (Shulchan Aruch and Mishna Berura 550:1, Maharam Mibrisk 3: 29, Nitei Gavriel Chanuka 60: 3 et. al.) Horav Shlomo Miller’s Shlit’a opinion is similar.” In this particular case, the Rov’s opinion is also that one should treat Assarah Betevets like the other day Taanesim.” In your case, there may be additional leniency when the Sheva Brochos begins during the day before the Shekia (sunset). You would have to wash and begin the Seuda at that time. Altough, in our latitudes it would be around 4.30 PM, and as you told me the Sheva Brochos is called for 8.30 PM, however Horav Shlomo Miller’s Shlit’a opinion is that if you can summon ten people and was early it would be beneficial. Therefore, as you told me you have B’H a large family at home, you may want to complete a Minyan at home and daven Mincha and then wash already for the Sheva brochos, before the Shekia. You will have to have those attendants eat some bread during the in between hours to avoid a Hefsek or separation of the parts of the Seuda.