I let my contractor try the old hot tar and hydraulic cement trick but it clearly didn't work.

Then again I dont want to over pay for it which is the vibe Im getting when I see a few of these estimates.btw I just got off the phone with an excavator who said he will give me a bid without cement, also stated that he doesnt do concrete work...only excavation etc.

Input is 2 floors house, the first floor has cement floor, the second is covered with plywood.

But there are roofers that will work during the winter and you can put cement under a hood with a huge heater to cure it, but it isn't optimal.  

The crawl space is otherwise very clean and has a cement floor.

Glad she did.Anyway, I have used D&G Cement Company for a Redford rental.  

Also, there is the crack running across the floor of the garage so there is a possibility the cement may have shifted down lower allowing water in.

Professionals drill (two feet or the longest masonry bit available) into the hole every 24 inches around the exterior and interior (if the basement is not finished) perimeter of the building and spray the chemical into the hole.After you have sprayed the chemical in the hole patch the hole with cement so the rain doesn't flush the chemical out.

One property I was shown had obvious structural damage on the porch (the cement was buckled in and up).  

If its cement block it should be firm if bonded to the block.