I split my gedcom data into several smaller files and do them one at a time.
I’m aiming to keep my file sizes to about 1000 people each file, this way as you work down the list of wikitree ged matches checking and comparing them it’s not such a massive task.
Depending on which program your data is stored in you should hopefully see a way of exporting a partial gedcom file.
This way (depending on your total file size) you could just split it via you parents if less than 5000, or if more you could split it by grand parents and so on.
Should your data source not let you split the file, you may just need to use a free program like PAF5 link: https://www.familysearch.org/products to just load the gedcom file and then export it in parts.
Hope this helps