I’ve always had a bad experience transferring more than a handful of files over MTP, but if you’re using Linux, the easiest way is to first find out your phone’s IP address (the ‘WLAN IP’ you can see in the developer settings, or if you don’t have developer mode enabled, the ‘IPv4 Address’ you see if you go to Settings → WLAN → long-press on your current connection → Details). Once you know the IP, you can enter:
sftp://192.168.178.123 #replace the part after 'sftp://' with your phone's IP)
in the location bar of your file manager. Add it to your bookmarks so you don’t need to manually re-enter it all the time. Once that’s done, you can wirelessly transfer everything you need. Of course, the tradeoff is that wireless transfer is often slower.