このシチュエーションの「これまでより」は
much less than
not as much as
を使って表現します。
ーI will see my family much less than I have been able to the last few years once I have moved to Europe.
「ヨーロッパに引っ越したら、ここ数年会っていたより、家族に会う回数が減るだろう。」
much less than で「〜よりもっと少ない」
ーNow that I'm moving overseas, I don't think I'll see my parents as much as I have been able to while living in Japan.
「海外に引っ越すので、日本に住んでいる時に比べ、両親に会えなくなる。」
not as much as 「〜と同じ程度ない・〜ほどでない」
ご参考まで!