hi, as we went 6 times in Mongolia maybe we can have some ideas for you
first at all you must know that nov is cold and so you must have warm clothes and warm sleeping bag. temperature are negative untill -30... be ready of that
even on Ub you can find and buy some cashmere clothes and underpants, and a warm dell...
ideas for 6 days in november: of course you can make a jeep tour or toward gobi desert or towards kharakorim and its area and so make a lovely tour. but if you are alone this will be maybe expensive as it's 110 euro per day. if you are a small grouop tis is maybe the right solution as 100 euro per day if for all the group, so you divide betwen your own group 110 euro. in a jeep you can be 4 + the driver, in a mini van untill 6-7
why not make a homestay to a nomadic family? you can maybe join then by bus and they will pick you at bus station to drove you in their winter camp and so divide tradionnal life? this is an unforgeatable experience we made several times. be carreful as on witner the ger aren't heated, when you go to bed the fire will slowly stop untill the morning and so it's cold, so ahve a warm sleeping bag for extreme temperature, even the fmaily can give some blankets better to have also your own one!
it will be really difficult to find to make horse trek as realyl cold and bad weather to stay outside all the day and generally all agencies end the season mild or end september. but you can find maybe something around kosgol lake, also guest hosue stop mild or end of september everywhere, but of course a few stay open. kosgol lake can be reached by bus but need 2 days to go.. so too much as only few days in mongolia
maybe fairfied guest house in tseterleg who is near Ub (one day trip by bus) can be open and have horse to rent with a guide?
maybe you can see my website terramongolia.com and found some more ideas and contacts to prepare your trip in november and of course feel free to contact me to have more inforamtion
we have a good and reliable contact in Ub who can pick you, lodge you in small guest house 6 euro per day and head and it's not so far from downtown and can help to any project you have (rent a jeep, homestay to family...) can give some advice... you can contact just to see if this cna helps you mejet69@yahoo.com
hopes you will have the most wonderful trip of your life
cheers