Does the collation of ENUM columns impact their size?
No difference.
ENUM is stored as a 1- or 2-byte number, where 0 maps to the first item in your list.  You deal with the column as a string, but the disk only sees a number.
2-bytes is used only when there are more than 255 options.  There are some who shun the use of ENUM altogether; there are some who frown on more than a few options.  I say use ENUM for a small, unlikely to change, list of options.
It may be possible to get charset or collation problems if you aren't consistent in database and connection specifications.