With only 4-5hrs/wek, I'm not doing a large overall volume anyway, so think I can safely add in some intensity with this approach.
Assuming an intent to exercise 5 hours per week, such a schedule would support one to 1.5 hours of work at, near or above LT. This could support 30 to 40 minutes of VO2 max work.
I've been doing something about like that during winter for years. I still end up losing a little endurance and hill climbing ability, but at least I start the Spring with some snap.