Either way, one is not allowed to pour hot water into the wine since one is focused on being precise and that would be too much of a loss of focus (tosfot 106b, and Bach). This law applies to anything similar to this. It is also written there in the name of Rabeinu Tam that it is forbidden to do these on a week day as one my lose focus and leave to do other things, but on the Shabbat when the table is all set, one can wash hands and then make kiddush. The same law applies to making havdala and then eating. See what is written in siman 174

The Shela writes that each day, before washing for bread, a person should give a prayer for the food he receives from G-d, and if he forgot to say this prayer until after he washed he is allowed to say it before saying the beracha on bread. And the world has a custom to say tehillim 23 between washing and hamotzi (see Siman 235:2 - where the Rema says that one doesn't break within the meal but one does break before hamotzi to say Shema and other prayers that were missed). The Rashal writes that the host should let the greatest man wash last (to allow him to talk until the end/or to not cause him to pause for too long..), but if he was asked first to wash and he chooses to wait till later, this is a transgressions since he is causing others to have a break, rather he should wash and sit down and not speak, and if they ask him a dvar tora he is permitted to stop. End of words of Rashal. See Sman 167:5 (where the SA lists thing that should be at the table in preparation for the beracha). And the Bach writes that it is forbidden to speak, even with divrei Torah, and even the sitting down is a hefsek as the Rema writes (ie, waiting more than 22 amot). With this in mind, a great man can choose not to wash first since we are more concerned when the person saying the beracha has to wait, as opposed to those that are listening. If the guests see that it is taking too long, they can take a piece of bread and recite the blessings for themselves

The tosfot in Sota prove this point from the case of a Metzora. A metzora was not able to do semicha on the sacrifice immediately before the slaughter as they were not allowed to enter the Azara. What they did was do semicha outside the entrance gates (Nikanor gates) and then the kohanim to walk the animal to the Mizbeach for the sacrifice. The distance between the gate and the alter is 22 amot and we see it was not a hefsek (the semicha needs to be just before the sacrifice). But I have a problem. This braita is brought in zevachim 33a to argue prove that a small amount that enters is not considered entering until the entire person enters (otherwise, why doesn't the metzora put his hand inside for smicha and then do shchita right there at the entrance). This question is origonally based on the assumption that we are talking about chachamim that you can shecht anywhere in the Azara, and then concludes that it is according to R Yehuda that only by the mizbeach is fine. But I have an issue, let us just say...... (not sure), rather we must conclude that if you move from one place to another (ie the 22 amot) it should be a hefsek. Even small amount of walking. That is how the mishne in Middot (end of ch2) seems to imply that in the place of smicha you need shchita. This needs analysis. (Look at siman 8,13 where the SA says that if you make a blessing in your home on tzitzit and then walk to shul you need another blessing for tallis as the walk is a hefsek. Look also at Siman 181:6 about waiting after mayim achronim). And it requires analysis on what it says in Yora Deah 19 where the psak is (if the slaughter house is messy) to say a bracha outside of the slaughterhouse at a distance of 4 Amon as it needs to be in its place (even bracha achrona 184 needs to be in its place. All the more so the first bracha. I looked at the Aguda in chulin (where it says 4 amot) and the 4 amot seem to be in the same house. This is what is mentioned in Shabbos "someone who wants to drink in the washhouse, should bless in the outside room since it is like a corner to a corner". But according to tosfot even corner to corner would be a hefsek and this is the prevailing opinion since it is no less that speaking. Therefore the position of the Rema in Yore Dea needs further analysis.