Answer
Use a new 10.6.23.0/24 subnet for this site.
Then add a new P2 at the main site for 192.168.2.0/24 to 10.6.23.0/24.
At the remote site add a new P2 for 10.5.35.0/24 to 192.168.2.0/24 and add the NAT address field to 10.6.23.0/24.
The 1:1 NAT setting is no longer required as route-based IPsec is not supported in FreeBSD 10(pfSense 2.3.4) hopefully in 2.5.
Thanks to pfSense support that gave me this valuable information.
https://www.netgate.com/blog/pfsense-2-5-and-aes-ni.html