Retirement tax questions

Can we carry over into 2019 even if we are not eligible for a ROth in 2019either? Also, what are the penalties? Will we owe the 6%?

We currently have an excess Roth in 2018 and 2019. Is it possible to carry the 2018 Roth into 2019, then recharacterize it to a traditional IRA to avoid the 6% penalty from 2018 passing the 12/31 deadline...and then carry the 2019 Roth into 2020 and then recharacterize it to a traditional IRA too?