Inheriting 100k

Recently, my grandfather passed away, and I will be inheriting about £120k. I already invest in a stocks and shares Isa investing my mainly in the s&p500.

I am wondering whether it would be better investing the money into my Isa over several years so as to take full advantage of it then being tax free. But then I wonder if I will be losing out on not having the rest invested during that time. Any thoughts would be appreciated.

I am 29,so am in no rush to make any decisions.