Yes you H4 I-94 can be extended at Canada or Mexico border.
https://www.am22tech.com/usa/news/h4-l2-ead-auto-extension-uscis-policy-change/
https://www.am22tech.com/i94-extension-laredo-tx-border/
https://www.am22tech.com/passport-renewal-i94-extension-san-diego-us-mexico-border/
https://forum.am22tech.com/t/i94-extension-in-usa-questions-answers/11818/4?u=kalpesh_dalwadi