Could Democrats end up with 60 US Senate seats by 2021.

Warren(D-MA) or Sanders(D-VT) will be President and Temporarily succeeded by a Republican until the 2021 special election winner is decided. 34 Democratic seats.
Before the 2021 special election in MA or VT.
35)RI(Reed-D)
36)DE(Coons-D)
37)MA(Markey-D or Kennedy-D)
38)NJ(Booker-D or whoever Governor Murphy-D appoints if Booker-D becomes VP).
39)OR(Merkley-D)
40)IL(Durbin-D)
41)NM(Lujan-D)
42)VA(Warner-D)
43)NH(Shaheen-D)
44)MN(Smith-D)
45)CO(Hickenlooper-D)
46)MI(Peters-D)
47)ME(Gideon-D)
48)AZ(Kelly-D)
49)NC(Cunningham-D or Smith-D)
50)IA(Greenfield-D or Franken-D)
51)KY(McGrath-D)
52)GA regular(Ossoff-D or Tomlinson-D)
53)KS(Bollier-D)
54)MS(Espy-D)
55)TX(Hegar-D)
56)SC(Harrison-D)
57)WV(Swearengin-D or Ojeda-D)
58)TN(Mackler-D or Yarbro-D)
59)MT(Collins-D or Mues-D or Neumann-D)
60)AL(Jones-D)
60/61)GA special election runoff(Lieberman-D)
60/61/62)MA special(Kennedy-D or Pressley-D).