There are no hotels on Seabrook Island only homes/condos/villas.
I'm gonna give it to you straight--you're going to have a challenging time finding something. Many Easter rental guests arrive on Saturday, April 24 for the week. Finding a weekend rental for next weekend will be difficult.
First stop, contact my friend Nancy at
Coastal Getaways. She manages 70 properties on island.
If she doesn't have anything, hit
Homeaway's website. You can search availability by date. **I just checked, and it does appear that at least one of the properties Nancy rents is available.
Good luck!