Lager yeast performs best at a steady 55*. I usually cold crash down to 48* for two or three months before carbonating. The extended condition time after all is the German word "lager."
At a temp of 60-70 the yeast will still produce beer, but it will also create a lot of fruity esters and not finish as cleanly as style guidelines stipulate. A lager should be crisp and clean with little to no off flavors. I am sure you will make fine tasting beer, but I fear it is not going to be a lager.
. on tap: easy virtue blonde, fruity monk belgian wit. primary: American pale ale, American stout, blow your top steam, and heffewitzen