What would it take for the Democrats to minimize losses in 2018 for the Senate?

[West_Midlander]

In Congress Infinity, I modified a 2018 scenario & maxed out stats (all 5's) for Dems/Independents, to run an (implausible) best case scenario for Dems/Indies in 2018.
Democrats and Republicans each have 49 seats, Democrats win each of their states with percentages in the 60s-70s. Republicans lose in the 2016 Clinton states + TX (yes, Cruz), MT, AZ, ND, WI, MI, IN, OH, PA. Republicans only win in UT, WY, NE, TN, AL and California.
King is re-elected in Maine (likely will side w/ Dems). Bill Weld runs as an Independent and wins a three way race in MA (will likely side w/ GOP most of the time), Warren finishes third with <24%. A three way race in California leads to a GOP win as an Independent is right on Boxer's heels and siphons off half of her votes.
Senate is 51-50 Republican (w/ Mike Pence's vote).
Since even this highly implausible scenario looks so dismal. Realistically, What would it take for the Democrats to minimize losses in 2018 for the Senate? What would the results likely be?

[Kingpoleon]

Force Republicans to spend money in Nevada, Arizona, and Texas by focusing on those states.