When are Democrats likely to regain control of the US Senate? 2020 or 2022 with a Democratic POTUS?

2020
Democrats will need a net gain of 4 seats if they don't win back the US Presidency.
Democrats are going to lose 1 Democratic held US Senate seat up for re-election in 2020.
AL(Jones-D) Sessions-R, Tuberville-R, or Byrne-R.
Democrats need to win 5 Republican held US Senate seats up for re-election in 2020.
CO(Gardner-R) Hickenlooper-D
AZ special(McSally-R) Kelly-D
NC(Tillis-R) Cunningham-D
ME(Collins-R) Gideon-D
IA(Ernst-R) Greenfield-D
Democrats are going to pick up CO,AZ special, and NC.
2022.
If Democrats occupy the US Presidency, Democrats need a net gain of 1 seat.
Democrats are going to hold onto every Democratic held US Senate seat up in 2022 including AZ(Kelly-D).
Democrats are going to pick up Republican held US Senate seats up in 2022 in
PA(Toomey-R) vs Lamb-D
WI(Johnson-R) vs Kind-D