Let's do our own analysis.
Currently the senate is 51R/49D.
Lets only look at seats that may flip:
AZ seems likely to go from R to D (Jeff Flake's seat. Ironically Trump driving him out may cost Republicans a seat)
NV could go from R to D
TN has a shot to go from R to D
TX can go R to D (Cruz v Beto)
ND is looking to go D to R (Heitkamp has slipped)
MO could go D to R (McCaskill is the incumbent D in that red state)
IN could go D to R
FL could go D to R
MT could go D to R
WV D Manchin is in a red state
Republicans have more chances with a number of Dems in states that Trump won. I can add MI, WI, OH and PA to that.
So if the Dems do get control after this election, it would be a monumental loss for Trump and his Republicans.
Democrats will still probably win 70% of the senate elections - but that won't do as they defend 26 seats to 9.