Hi Billy,
There are a few ways you could approach this:
1. Use the Append Geoprocessing tool in ArcPro to append the data from the original survey layer to the new survey layer.
Note - This method has a more robust handling of global ids, so it is preferable to the second approach described here (appending via ArcGIS Online) if your data has repeats or attachments.
Here is a video that demos this method of appending.
Also if you have editor tracking enabled, this post discusses a way to preserve those values.
2. Use the Update Data>Append Data to Layer option in ArcGIS Online to append the data from the original survey layer to the new survey layer.
This knowledge base article includes the procedure for this method. Note that in order to maintain relationships, sync must be disabled, and that while this article says that attachments will be maintained, there are instances where this is not the case.
3. Another option for changing the field length or field type of a field is to create a new field within the existing feature layer, populate it with the original field contents, delete the original field, create a new field with the same name as the original field but with the desired field length/field type, and populate it with the data from the holding field.
Thanks,
-Barbara