Question about changing timelines

I started leveling up my new alt in wotlk through Chromie and everything was going good until I tried to do some dungeons by myself, that's where I got completely destroyed so I figure out it was because Chromie scales everything to my level and I actually need 4 more people to do those dungeon.

So the question is: can I change timeline with chromie so I can do the dungeons solo and then change back to keep leveling in Northrend? I'm already in the wotlk timeline btw