Are you planning on doing this because your bored with your current phone?
I see alot of posts like this be it Apple or Android people downgrading because they basically bored, but that boredom can & usually does turn into a regretful & costly decision.
The SE 2020 is not as good as the 11 period, it's looks dated, battery life isn't as good, camera isn't as good, the screen is to small for any decent media consumption ect ect.
If your doing this mainly because you want a smaller phone then wait for the iPhone 12 5.4" which will have better spec's than the iPhone 11 offer 5G aswell and if your planning on selling your 11 then that should take a decent chunk of the price of the iPhone 12 5.4"
The SE is for people like me which i have & love that doesn't want to spend alot of money on a phone, don't care it looks dated, camera good enough for my needs, screen size is perfect because i don't game or watch movies ect on it apart from the odd YouTube video & the battery life last me all day because i'm not glued to it constantly.