In regards to crossing points, at least in Poland, they anticipated the loss of bridges and took some preparation to counter the loss. There are a small number of locations along some of the major rivers where ferry points were created although I don't know if these were for civilian "every day" use or were made for anticipatory military use.
In other places concrete ramps where installed and in some cases pontoons where left in situ implying that some level of pre-placing bridging equipment was made. In other places, parts of the river bank had been prepared but only to the extent of cutting ramps into the embankment. I should also point out that there were very few of these sites, not every town with a riverine bridge had a pontoon/ferry crossing point.
I'm not saying these pontoons would still be in place during the war or left undamaged but the concrete/earthen ramps or ferry points may have survived in some useful capacity (unless of course, they were sabotaged to prevent enemy use as the various armies fought back and forth across Poland).
I must state that while I saw a few of these crossing points myself in 2010, I only saw places in central and eastern Poland and I have no idea how widespread the practice was. I also don't know if the pontoon sites were under the authority of the Polish government or military or the Soviet military and people I asked didn't know for sure, they thought it was Polish military but couldn't be certain.
I do not know if that situation exists closer to the German border where it could be argued that you don't want prepared sites that could assist the enemy in crossing your rivers.
A good example of the pontoon sites and the first one I "discovered"
https://www.google.com/maps/place/Zj...6!4d18.1672789